You can automatically perform actions on your mail as it is delivered to your account. To configure rules, open the Settings → Rules screen. There are 4 sections:
Discard — if a message matches any of the rules you add in this section, it will automatically be permanently deleted and you will never see it. No further rules will be processed, even if they would have otherwise applied to the message.
For extra safety if you use discard rules, tick the option "Do not discard messages sent by my contacts". This will help make sure you don't accidentally discard important email.
Messages that FastMail detects as spam cannot be filtered with these rules; see custom sieve script for an advanced alternative.
When you discard, forward or organise your mail, you create a rule that only applies to messages matching a certain criteria.
Decide which part of the message you want the rule to look at:
Fromaddress of the message.
Ccfields. It also looks at the
X-Delivered-toheader, which contains the recipient address from the original SMTP envelope (i.e. the email address the sender actually sent to). The rule will apply if any of the addresses in these fields match.
Subjectof the message.
List-Idheader of the message.
Choose how it matches. For sender/recipient, the options are:
email@example.com, or just a domain, e.g.
@example.com, or just a user part, e.g.
joebloggs@. If you do not enter an '@', one will automatically be entered either at the beginning or end, depending on whether we think you're trying to match a user part or a domain.
For subject, message text or mailing list ID, the options are:
In general, we recommend you always use "contains", as there may be extra spaces or an unexpected
< character at the beginning or end of the message text/mailing list id.
Finally, type in the text you want to match against.
Advanced users may be interested to note we also support matching criteria via glob or regular expressions. For full control, we also support writing a custom sieve script to process your incoming mail.