Hi,
After a minor incident of some phishing emails being sent purporting
to be from
bitfolk.com, on 3 June I tightened the SPF record of
bitfolk.com from ~all to -all. This basically says that ONLY the
hosts listed in the SPF record are permitted to use a
bitfolk.com
envelope sender on email, and that any other host trying to do so
should be rejected.
I have since noticed that some customers are using traditional
server-side forwarding, e.g. on role addresses, to send BitFolk
emails to a group of people, and some of those recipients are doing
as asked and rejecting the email. More are probably silently
discarding or filing the mails away in spam/junk folders.
This happens because when your mail server forwards an email from
e.g. billing(a)bitfolk.com through role(a)yourdomain.co.uk and out to
joe.bloggs(a)example.com, your mail server is pretending to be
billing(a)bitfolk.com. Since you do not match bitfolk.com's SPF
record, the mail server for
example.com rejects the email (unless
configured otherwise).
Unfortunately we can't go back on this configuration. It's just the
way that email works in the 21st century. Server-side forwarding of
email in this way is not something that can be expected to work any
more, unless you control both the recipient address and every
address it expands out to.
So what can you do if you currently do forwarding of addresses like
this?
- The generic answer is Snder Rewriting Scheme:
https://en.wikipedia.org/wiki/Sender_Rewriting_Scheme
- A more limited answer is to run a real mailing list of some sort,
so that, for example, billing(a)yourdomain.co.uk goes through a real
mailing list manager like majordomo or Mailman, is rewritten and
sent out to the people who should receive it.
- If you control or have strong influence on all recipients, you can
configure them to allowlist particular senders.
- You can set up real mailboxes for your role accounts and have
interested parties download the email by IMAP or POP.
I'm sorry that this change has broken some previously-working
forwarding setups. It isn't something we can revert though (and
indeed, it will have to get stricter, with additional DKIM and DMARC
to come).
Cheers,
Andy
--
https://bitfolk.com/ -- No-nonsense VPS hosting