Fastmail domains, a list
 

Fastmail has many domain alternatives.
https://www.fastmail.com/about/ourdomains

Up to 600 aliases are allowed per account.
https://www.fastmail.com/help/receive/aliases.html
https://www.fastmail.com/help/send/identities.html

And with Fastmail subdomain addressing, unlimited on-the-fly address creation.
https://www.fastmail.com/help/receive/addressing.html

Fastmail domains (117):

• 123mail.org
• 150mail.com
• 150ml.com
• 16mail.com
• 2-mail.com
• 4email.net
• 50mail.com
• airpost.net
• allmail.net
• bestmail.us
• cluemail.com
• elitemail.org
• emailcorner.net
• emailengine.net
• emailengine.org
• emailgroups.net
• emailplus.org
• emailuser.net
• eml.cc
• f-m.fm
• fast-email.com
• fast-mail.org
• fastem.com
• fastemail.us
• fastemailer.com
• fastest.cc
• fastimap.com
• fastmail.cn
• fastmail.co.uk
• fastmail.com
• fastmail.com.au
• fastmail.de
• fastmail.es
• fastmail.fm
• fastmail.fr
• fastmail.im
• fastmail.in
• fastmail.jp
• fastmail.mx
• fastmail.net
• fastmail.nl
• fastmail.org
• fastmail.se
• fastmail.to
• fastmail.tw
• fastmail.uk
• fastmail.us
• fastmailbox.net
• fastmessaging.com
• fea.st
• fmail.co.uk
• fmailbox.com
• fmgirl.com
• fmguy.com
• ftml.net
• h-mail.us
• hailmail.net
• imap-mail.com
• imap.cc
• imapmail.org
• inoutbox.com
• internet-e-mail.com
• internet-mail.org
• internetemails.net
• internetmailing.net
• jetemail.net
• justemail.net
• letterboxes.org
• mail-central.com
• mail-page.com
• mailandftp.com
• mailas.com
• mailbolt.com
• mailc.net
• mailcan.com
• mailforce.net
• mailftp.com
• mailhaven.com
• mailingaddress.org
• mailite.com
• mailmight.com
• mailnew.com
• mailsent.net
• mailservice.ms
• mailup.net
• mailworks.org
• ml1.net
• mm.st
• myfastmail.com
• mymacmail.com
• nospammail.net
• ownmail.net
• petml.com
• postinbox.com
• postpro.net
• proinbox.com
• promessage.com
• realemail.net
• reallyfast.biz
• reallyfast.info
• rushpost.com
• sent.as
• sent.at
• sent.com
• speedpost.net
• speedymail.org
• ssl-mail.com
• swift-mail.com
• the-fastest.net
• the-quickest.com
• theinternetemail.com
• veryfast.biz
• veryspeedy.net
• warpmail.net
• xsmail.com
• yepmail.net
• your-mail.com

fastmail.uk
 

That domain is not listed, although I have an alias created for that domain.

Are you sure your alias is not in the (listed) fastmail.co.uk domain?

fastmail.uk is a valid Fastmail domain
 

Fastmail has owned the fastmail.uk domain since August, 2015. The help link is currently in error. You can create a new Fastmail account or add an alias at that domain.

Bill

I'd still like to know why there appears to be restrictions on some local names you can choose as a prefix to go with any of those aliases, i.e., why some local-part names always result in "already been taken" when I cannot believe they are.

Restrictions to local-part of address to prevent fraud and confusion
 

Of course, in many cases the alias is already taken by another user. Since any user with a current account type can add up to 600 aliases, anyone can choose a specific local-part alias at every Fastmail domain (such as “jane” at every domain). But I think you specifically mean a prefix to a local-part, such as “support” or “sign” or “fastmail” or “fastmailuk” added at the start of a local-part. For example, these are not allowed:

• support@fastmail.com
• support10024thisisrandom@sent.com
• signuphere@mm.st
• signupatalldomains@fastmail.com
• fastmail@fastmail.uk
• fastmailuk77y34900j@sent.com

I’m sure this is to help reduce confusion and fraud. Aliases can also be used for subdomain addresses and websites based on the subdomain. Fastmail doesn’t want any use to set up the email address “supportme@fastmail.com” or the website “www.support.fastmail.uk” or any variant starting with that prefix.

You can use you own personal domain(s) and add nearly any local-part you wish (subject to restrictions on email addresses and host names in the internet standards).

Bill

There's room for one more.
https://fastmail.blog/2016/12/15/fastmail-ca

That's exactly what I mean. Three I stumbled into are anonymous, register, account.

So it's FastMail imposing the name restriction not some general alias local-part restriction. Wish they would post the list of all words in this category.

When it comes to security related restrictions, it may be prudent to not publish such a list. If I was in charge I don't think I would let others know the details of those restrictions. You can always try the word and see if it works. Get your own domain if you want to be fully in charge of such aliases.

Bill

There is a (public) list:

• abuse
• admin
• administrator
• hostmaster
• info
• is
• it
• list
• list-request
• majordomo
• marketing
• mis
• news
• postmaster
• root
• sales
• security
• ssl-admin
• ssladmin
• ssladministrator
• sslwebmaster
• support
• sysadmin
• trouble
• usenet
• uucp
• webmaster

https://webmasters.stackexchange.com/a/105020

Strictly speaking some names on that list aren't based on any official standard, only on the current practice of certain providers, plus a modicum of common sense.

Also ones I had found (anonymous, register, and account) are not on that list either and some on that list are allowed by FM. I guess when I have a moment I should submit a ticket and ask FM if they can send me a list or post it.

I expect the aliases below:

1. Fastmail.me
2. FM.me
3. Fastmail.io
4. FM.io

can you support that?

Nearly all of the posters here are users of email services. So maybe you should ask “can Fastmail support that?”

If you meant to ask if Fastmail could support those four domains (as opposed to aliases), Fastmail does not offer any domains ending with .io or .me as standard domains for aliases. Of course, if you own any of those four domains you can use them for Fastmail email if you have a Standard or better account.

Are you asking whether those local-parts of email addresses are available as aliases at Fastmail domains, such as Fastmail.me@fastmail.com or Fastmail.me@eml.cc? As I stated earlier in this thread, you can’t use aliases which begin with “fastmail” for use with Fastmail-owned domains. So no, you can’t use Fastmail.io or Fastmail.me as aliases at Fastmail-owned domains.

But you can use aliases such as “FM.me” and “FM.io” at Fastmail domains if they are not in use. I just created these at a Fastmail domain testing this, so now you won’t be able to use those two aliases at that domain. This shows why I believe that it’s a bad idea to publicly discuss specific email addresses or domains which don’t yet exist - others can grab that address or domain before you do!

Bill

All domains (not aliases, see comment above from Bill) are not available, Fastmail.io is owned by FastMail, but not in the list (yet).