Forwarding and automatic replies

Forwarding and automatic replies are both set up as Sieve rules in Account > Filters, which requires the Operator or Shadow plan. Before you forward, read the caveats below. Forwarding can make legitimate mail fail authentication checks at the final destination.

Forward mail

keep;
redirect "you@example.org";

redirect hands the message to another address, and it cancels the implicit local delivery that Sieve normally performs. The keep line keeps a copy in your ITProMail mailbox. Without it, mail goes only to the forwarding address. To forward only some mail, wrap both lines in an if test.

Automatic replies

require ["vacation"];

vacation :days 2 :subject "Away" :addresses ["you@example.org", "you@example.com"]
  "Thanks for your message. I am away and will reply when I return.";

The sender receives at most one reply per :days period. :addresses tells the rule which addresses are yours, so replies are sent only for mail addressed to you. Keep one vacation rule in your active script, and remove it when you are back.

Caveats for forwarding

• SPF. SPF checks whether the server that connected to the destination is allowed to send for the sender's domain. A forwarder is a different server, so the original sender's SPF check generally fails at the final destination.
• DKIM. A DKIM signature usually survives forwarding, as long as nothing changes the signed headers or body. Footers, subject tags or rewritten content added along the way break it.
• DMARC. DMARC passes when SPF or DKIM passes and aligns with the From domain. If a sender relies only on SPF, a forwarded message can fail DMARC at the destination, and the receiver may quarantine or reject it.
• Sender rewriting. Some forwarders rewrite the envelope sender using Sender Rewriting Scheme (SRS) so that SPF can pass again. Whether that happens depends on the forwarding path. This guide does not describe how ITProMail handles envelope rewriting on forwarded mail; contact support@itpromail.com if you need that detail.
• Loops. Do not forward to an address that forwards back to you. Test with a message you can trace.

Practical advice

Forward only the mail you need, and keep a local copy of anything you cannot afford to lose. After you set up a forward, send a test message from an account you control, then open its raw headers at the destination and look at the SPF, DKIM and DMARC results. If the destination is a provider with strict filtering, expect some forwarded mail to be marked as spam or rejected.

Related guides: Sieve basics, Sieve examples, and DMARC reports.