Increased user security, upgrading Diffie-Hellman parameters to 2048 bits

For non-technical users, the short version is that if you’re using a modern, up-to-date web browser, mobile device or mail client to access FastMail, then there’s nothing you need to do.

If you’re using old or unusual software to access or send via FastMail, you might be affected and should read on.

What’s happening?

On 30 March 2015 we will be increasing the size of the DH parameters for DHE ciphers to 2048 bits. This will cause connection problems for old software that cannot handle DH parameters greater than 1024 bits.

1024-bit RSA crypto is generally being phased out as insecure and has been for at least the last five years.

Breaking DH parameters is generally understood to require the same amount of computation as a RSA key of equivalent size. Therefore, the recommendation is to increase the size of DH parameters in step with the size of RSA keys.

If we don’t upgrade our crypto to 2048 bits for the general case, we’re compromising the security of all our users for a few that have old clients. We don’t consider that to be acceptable.

Will this affect me?

The main software we’re aware of that will be affected is iOS 5 and Java 6 and 7 (which often means business software that sends through our authenticated SMTP service).

If you’re unsure if you’re affected, you can test right now by pointing your software at (web) or (everything else). These servers are using the new config that will be rolled out on the 30th. Note that you shouldn’t use these names permanently; this is a test service and does not have the same redundancy as the main FastMail services.

If you can access your mail as normal using these servers, then you have nothing to worry about.

If you can’t connect through the beta servers but can through the main servers then its quite likely that you are affected and you will need to either upgrade or reconfigure your software, or switch to our “insecure” services at (web) or (everything else). Using the insecure service is not recommended as it uses encryption that is known to be weak or broken.

Please note that we’re unable to help you upgrade or reconfigure your software, particularly for those Java business apps. You’ll need to contact your software vendor for that.

Further reading

If you’d like to read more about perfect forward secrecy and DH param lengths, the following technical articles may be interesting to you:

Posted in Technical. Comments Off on Increased user security, upgrading Diffie-Hellman parameters to 2048 bits

XMPP security improvements

We’ve just rolled out an update to our XMPP service to give it the same level of TLS encryption support that you’ll find in our IMAP, POP3 and SMTP services. It now supports TLS 1.2 with modern ciphers. The changes mean we now get an A rating on the XMPP security test.

If you didn’t know we had an XMPP service, or if you don’t know what any of this means, then you can ignore it. Everything should just continue to work!

Our XMPP service has lagged behind our other services for a while because our XMPP server, djabberd, has problems with TLS >1.0 due to deficiencies in Perl’s TLS libraries, and has resisted our best efforts to fix it. We’re hoping to replace it with another server in the next year or two so to avoid having to do a bunch of work that we’d eventually throw out, we decided to follow the same model that we use for IMAP, POP3 and SMTP. We added XMPP support to nginx’s mail proxy, and then let it do authentication and encryption termination, both tasks which it excels at.

Most importantly, nginx is well known as a highly stable and secure TLS server and receives a constant stream of updates. Any improvements we roll out in the future will automatically be applied to the XMPP service as well.

More information about the actual implementation in nginx is at

We’re quietly working on modernising our XMPP service. If that’s something you’re interested in then keep an eye on this blog over the next few months.

Posted in Feature announcement. Tags: , , . Comments Off on XMPP security improvements

Know how to identify genuine email from FastMail

Recently, we’ve seen an upswing in the number of attempts by criminals to steal FastMail accounts. We’re working hard to maintain our high security and keep them at bay, but we’ve also got three simple tips you can follow to keep your account secure.

1. Know how to identify genuine email from FastMail

All genuine email from FastMail is displayed with a white tick in a green circle next to the sender’s name in both the mailbox list and on the message itself. It looks exactly like this in the mailbox:

Green tick next to sender name in mailbox list

And like this on the message:

Green tick next to sender name in message view

If the email doesn’t have the green tick, it’s not from us.

Please note, we can only do this in our web interface and apps; it will not appear in other email clients. It will also not appear in our classic interface; we recommend users upgrade to our current interface for increased security.

Always look for the green tick before trusting emails supposedly from FastMail.

2. Look for the green badge before logging in

When logging into our webmail, always look for a green badge in the address bar of your browser with the text “FastMail Pty Ltd”. Phishing sites (scam websites that try to steal your login details) can easily clone the look and feel of our website, however they can’t clone the green badge.

The badge looks like this in Google Chrome:

Green EV SSL badge reads FastMail Pty Ltd

And like this in Mozilla Firefox:

Green EV SSL badge reads FastMail Pty Ltd

And like this in Safari:

Green EV SSL badge reads FastMail Pty Ltd

And like this in Internet Explorer:

Green EV SSL badge reads FastMail Pty Ltd

And like this in Opera:

Green EV SSL badge reads FastMail Pty Ltd

If you don’t see the badge, you’re not at the genuine FastMail website.

3. Never reuse your FastMail password at another service

Your email is the key to your digital life. Almost every web service you use, such as Amazon, Facebook or Twitter, allows you to reset their password by sending a link to your email address. It’s vitally important to keep your email password secure, as it provides access to everything else!

When you reuse your FastMail password at other sites, you’re making it much easier for attackers to potentially break in to your account. Other sites often don’t have the same high security measures as FastMail (such as compulsory HTTPS, locked-down servers, etc.), which makes them much easier for criminals to break in to. If they hold your email address and the same password that you use for FastMail, the attacker can then access your email account and get into everything else you use online.

Always use a unique password for FastMail that you don’t use elsewhere.

Follow these three simple tips, and you’ll be protected against the vast majority of attacks we see.

Posted in News. Comments Off on Know how to identify genuine email from FastMail

FastMail app for Intel-based Android devices now available

Today I pushed an update of the FastMail app that works on Intel-based Android devices. We’ve had a few requests for this as more and more Android devices are now running on Intel CPUs. Happily, the Crosswalk browser engine we use in the app has had Intel support for a long time, so it was just a matter of adjusting our build system to be able to build two different versions of the app.

As usual, its available from the Google Play Store.

Posted in Feature announcement. Comments Off on FastMail app for Intel-based Android devices now available

Dec 24: Working at FastMail

This blog post is part of the FastMail 2014 Advent Calendar.

The previous post on 23nd December was the open protocol, JMAP. And this is the end!

Technical level: low

FastMail has been around for 15 years now, via a short detour as part of Opera Software and then back to being our own company again.

Some History

I was hired in 2004 as the fourth member of a small technical team in Melbourne. Rob M was living overseas at the time, so I worked with Jeremy (one of the original founders, he’s moved on to other things now) and Richard. We had no office, but I would catch the train and tram to Port Melbourne and work with Jeremy in his lounge room.

After working for a big corporate where (no joke) I couldn’t have a server to do my work for the 6 months I was seconded to New Jersey, because they needed longer than that to plan things, and where I only managed to wrangle a desktop computer to make into a server because my laptop had been purchased in Australia and wasn’t in their database… it was a breath of fresh air to be asked to specify the laptop that I wanted and have it delivered and waiting for me when I started.

Jeremy also had another company, and we moved in with them when they got some space of their own. We shared a house in Port Melbourne where we set up desks in the bedrooms, and then later a proper office in Melbourne CBD until they were sold in 2008. We moved to a serviced office on the 50th floor of one of the tallest buildings in Melbourne. The view was fantastic, though my ears always popped in the elevator! Jeremy stayed with ODG, so it was just the three of us working together.

After the sale to Opera, we doubled the size of the team and took a larger office on the same floor. I was lucky enough to get a transfer to head office in Norway in 2011-2012, and while I was away the team in Australia grew further and moved to our current office on William St in the Melbourne CBD (interestingly, our datacentre in New York is also on a William St — it hasn’t caused any misdirected mail yet). We have a great office of our own now, with plenty of space.

Office environment

We work in rooms with 2-4 people, with doors that can be closed (though they usually aren’t) and a boardroom that’s big enough for the entire team to get together for our weekly status meeting. If anyone is remote (working from home, travelling, etc) they join via video conference. We’ve been using AppearIn from our friends at Telenor.


We have a huge open breakout area with couches, table tennis table and kitchen.


The nice thing about working on computers on the other side of the world is that it really doesn’t matter where you are. We don’t treat the office network specially, everybody’s laptop makes its own VPN connection anyway – so we can do our work anywhere. Most of the team have children, and many of us work from home one or two days per week.

When we are in the office together, we frequently gather around whiteboards to nut out ideas. The great thing about smartphones is that everyone has a camera, so we all take a photo of the end result and keep it with us as we go back to our individual tasks.

A Small Business

The great thing about FastMail is that it’s a blend of startup and small business. We have the best bits of startup culture — flexible working hours, free coffee, snacks and drinks in the fridge, table tennis table, cake on Fridays (often shared with our friends at ODG, we still stay in touch). This is matched with the best bits of a profitable company — consistent revenue, existing infrastructure, decent salaries, and people who understand the business side of things as well as the tech.

My first question when I interviewed with FastMail was “do you have someone who knows how to run a business”, because I worked for a dotcom that went bankrupt due to poor business planning. I didn’t want to live through that mess again. FastMail has had steady growth every year for the last 15 years, thanks to our fantastic users who appreciate our product and stay with us.

Jobs at FastMail

As with any business, if the right person appears, sometimes you adjust things to create a role for them. Our tasks aren’t that fixed, we split the work between us to get the required jobs done.

Having said that, we have two specific positions opening up in our Melbourne, Australia office for early 2015:

These two people will be working on both our FastMail product and building the reference open-source implementations for JMAP.

If you have the skills we need, and the right to work in Australia (sorry, we can’t help with visas or sponsorships), then drop us a line at


Thank you to everyone who has been following this series, reading what we write. More than anything, people want to know they are bringing value to others. One of the best things about working at FastMail is that code we write is out there making people’s lives better almost immediately — that’s a great feeling. The positive feedback we’ve been receiving has made all the effort worthwhile, even last-minute scramble to get posts finished on the weekends!

Extra special thanks to all our customers. It’s your ongoing support that allows us to continue our passion of building email, calendar and contacts done right.

Wishing everybody a happy and safe holiday season.

Posted in Advent 2014. Comments Off on Dec 24: Working at FastMail

Dec 23: JMAP — A better way to email

This blog post is part of the FastMail 2014 Advent Calendar.

The previous post on 22nd December was the long awaited beta of contact syncing. The final post on 24th December is about our work environment.

Technical level: low

You can reproduce the demos by signing up a trial account at FastMail and trying for yourself!


FastMail started with IMAP in 1999 when it was still quite new. We have been involved in the standards process, and have watched while non-open protocols led the way on features, usability and reliability. We pride ourselves on the standards compliance of our server, but we have been frustrated by the lack of progress in the third-party client experience available to our users.

The fragmentation of server support for newer IMAP features means that clients either have multiple implementations of everything, with the complexity and bugs that involves, or fall back to lowest-common-denominator behaviour. Extending IMAP further just makes this situation worse.

Having a separate protocol (SMTP) for sending email, running on a different TCP port and with potentially different credentials provides opportunities for partial failures, where a client can send but not receive or vice versa. These issues can be caused by firewalls, by temporary maintenance on the server, or just misconfiguration.

Regardless, for the end user the result is confusion. This is a frequent support problem for anybody with non-technical users, and the addition of CalDAV and CardDAV — everybody wants calendar and contact sync these days — means yet another failure mode in the mix.

FastMail’s protocol

When we built our own client and API we had the benefit of years of experience. I had rewritten the Cyrus IMAPd internals with strong locking to allow reliable QRESYNC support. We benefited from the work done by the LEMONADE working group for mobile email.

We also hooked in to MBOXEVENTS and FUZZY SEARCH, building on standards in the backend to create a great experience for our users. We added non-standard conversations support to our server, and there is discussion on the protocol lists about standardising that in a way which is compatible with gmail and other implementations.

Our servers are in New York, and our developers are in Australia. Even on a good day, the ping times are over 230 milliseconds. Anything more than the absolute minimum number of round trips is felt very keenly.

The end result is a very efficient, stateless, easy to use JSON API which already provides a great experience for our customers.

A proliferation of protocols

We are by no means the only people to have this idea. Many companies are building APIs to access email. Here’s just a few of them:

None of these APIs are designed with a primary goal of enabling 3rd party clients to work efficiently, with few round trips and low bandwidth use, and they are all limited to a single vendor. To inter-operate, everything falls back to speaking IMAP and SMTP.

Enter JMAP

JMAP is FastMail’s protocol with the warts removed. We leverage existing standards like HTTP, JSON, and native push channels on platforms which have them – making it easy for developers to work with.

JMAP is friendly to mobile devices. By batching multiple commands in a single HTTP request, and having an efficient update mechanism, the radio works less, and battery life is increased. By using the platform push channels, JMAP avoids having to hold its own connection open.

JMAP is friendly to servers. A stateless protocol, there’s no need for the server to maintain a version of the mailbox view that’s out of sync with the current state, as IMAP does, just so that clients can use integer offsets to refer to messages.

JMAP is friendly to the network. Unlike IMAP which can send an unbounded number of unsolicited updates, in JMAP you explicitly ask for the fields you are interested in, and the update command can contain a limit — if there are too many changes, return an error and let the client load the view from scratch. If you’re not caching the entire mailbox locally, then re-fetching a few pages of index listing is better than getting 100,000 EXPUNGED lines down the wire.

JMAP is friendly to multiple clients. In IMAP, if you rename a folder or move messages, then the client which initiated the action can update their local cache, but every other client has to re-fetch everything – there is no unique message ID which follows the message. JMAP uses globally unique IDs for messages, so immutable data can be cached forever.

JMAP does everything. Instead of separate protocols with different syntax for sending email than for receiving it (and separate protocols again for contacts and calendars) JMAP combines them all under one protocol. Best of all, the push notification includes all tokens for each service, so you can synchronise changes to your entire mail account plus your contacts and your calendar in a single round trip — up to date immediately, the way it should be.

Open everything

The JMAP protocol is totally open and unencumbered.

FastMail commits to provide a reference server and reference client, as well as maintaining the specification document in collaboration with others and keeping an up-to-date test suite to allow verification of implementations.

Finally, we know IMAP, SMTP and the DAVs aren’t going away any time soon. No protocol will succeed unless it provides an upgrade path from where we are now, and a compelling reason to switch. We will provide a proxy which can talk to existing servers and present them over JMAP. If the proxy is run somewhere close (in network terms) to the legacy servers, then JMAP will be a better experience than speaking to the servers natively, particularly if you’re on a slow network or the other side of the world.

As more servers start talking JMAP natively, the baseline for interoperability will be raised beyond IMAP+SMTP.

Come and join us at and on the mailing list. Together we can build a better way to email.

Posted in Advent 2014. Comments Off on Dec 23: JMAP — A better way to email

Dec 22: CardDAV beta release

This blog post is part of the FastMail 2014 Advent Calendar.

The previous post on 21st December was about our file storage system. The following post on 23rd December promotes our standard for better email.

Technical level: medium

After more than a year of anticipation we’re very happy to announce today that we’re releasing CardDAV support into public beta test.

CardDAV is a protocol for reading, writing and synchronising contact data. It’s built into iOS devices and available on Android with an inexpensive third-party application. If you’ve ever wanted to have your FastMail contacts available on your mobile device (and vice-versa), then this is exactly what you want.

Obviously, since this is a beta, there are still a few pointy edges and non-working bits. The most notable thing is that the beta is currently only available to personal accounts, not to business or family accounts. This is because support for shared contacts is not ready yet and there’s some potential for data loss and inconsistent behaviour if you try to use shared contacts without proper support. We’re working hard on finishing shared contact support and hope to make the beta available to business and family accounts within the next couple of months.

CardDAV is only available to Full account levels and higher. Member, Guest and Lite accounts will need to upgrade to be able to use CardDAV.

So now all the disclaimers are out of the way, you can sign up for the CardDAV beta here: Instructions for connecting your client are still under development here:

The contacts story

An address book is a fundamental component of any mail system and FastMail has had one almost since the beginning. It’s always been stored in the MySQL database and available through the web client. For much of its history it’s been confined to the web client. A few years back we did add a read-only LDAP interface, which is useful for desktop mail clients that could support LDAP address books. It works fine, but being read-only severely limits its usefulness. Some time later mobile devices happened, and it became clear that something else was needed.

In 2011 the CardDAV protocol was published, largely developed at Apple to allow device contacts to be synchronised with a server. The protocol is very similar to the earlier CalDAV protocol (which we also use for our calendar) which is good as it allows us to share a lot of code between our calendar and contacts system.

Towards the end of 2012 we started to seriously appreciate the need for both an integrated calendar and device contacts syncing. We weren’t the only ones, as the Cyrus project had started to add support for CalDAV and CardDAV to the Cyrus mail server. We looked at a few options for calendar and contacts and decided that we would implement both on top of the support being baked into Cyrus, and work began in earnest. We decided that calendar was more important because we already had a contacts system and while it wasn’t perfect we preferred to focus our engineering effort on a clear gap in our product lineup. That work took the best part of a year, and we finally released the calendar to production in June 2014. At this point we were able to focus on CardDAV-based contacts.

The actual CardDAV part of this work is actually fairly simple. Unlike CalDAV, the backend server (Cyrus) doesn’t really need much special knowledge. It mostly just saves and loads contact cards as required. Calendar entries are more complicated; the server needs to know about timezones, recurring events, alarms, etc. CardDAV is much easier and if all we had to do was ship CardDAV support, we probably could have done so months ago.

The thing that made it more difficult came from the fact that we already had a contacts system and plenty of code fairly tightly integrated with it. It’s more than just the two user interfaces. The mail delivery pipeline also makes use of user contacts for spam whitelists and distribution lists, so we needed to teach these systems about a whole new storage system for contacts. Up until this time they had simply hit the database for this information. To make matters worse, we always knew that we’d need to roll out CardDAV to users gradually which meant that both the UI and the delivery code needed to be able to work with either. In short, we needed to abstract away the implementation details of the contacts storage, which took a few months to build, test and deploy. We ended up with a nice abstraction based on the JMAP getContacts/setContacts model, with a database provider behind it.

The next step was to write a CardDAV provider for our contacts abstraction. That was actually pretty easy because most of the code needed to access DAV resources was already available from our CalDAV work.

The last piece of the puzzle was the actual data conversion layer. The existing contacts system has a data model that doesn’t match up perfectly with the vCard format used by CardDAV, so we had to develop a mapping. Most of the fields have a 1:1 mapping (addresses, email addresses and phone numbers). What we call “online” fields, however, do not. Our “online” field group includes URLs, Twitter handles and chat IDs. vCard doesn’t group those the same way but more annoyingly, it doesn’t have a standard set of fields for representing these. It took a long time to develop and test a mapping that works most of the time. It’s going to need improvement as we go but it’s not bad for now.

What’s next

The next few months will include a lot more testing, polishing and responding to user feedback and obviously completing the business and family support. That will bring us to a full release where everyone will be quietly and transparently migrated to the CardDAV backend. We can then start to clean up a lot of old code, always a nice thing to do.

If you’re trying the CardDAV beta test, we’d love to hear what you think. Let us know on twitter or by emailing

Posted in Advent 2014, News. Comments Off on Dec 22: CardDAV beta release

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