Sender SMTP header

Hi.
Generally speaking, emails sent by RT are working fine (notifications when assigning, commenting, reminders…) but not when sending dashboard subscriptions.

I’ve seen that RT adds the “Sender:” SMTP header with the value user@servername (www-data@rt in my case). It’s blocked by policy by the email system. I’ve two options: ask the admin to change the rule that blocs my messages or change the value set by RT.

I prefer the second option. Is there any way of setting Sender’s value? I’ve been digging in the code a couple of days without luck.

I’ve read the answer in this post that sendmail is the responsible of adding this header, but configuring $MailCommand as testfile I can see the following headers in the mail sent by root while executing rt-email-dashboard:

X-Mailer: MIME-tools 5.510 (Entity 5.510)
Sender: root <root@my.host>
Subject: my.subject
Date: Tue, 26 Mar 2024 14:03:17 +0100
Content-Type: multipart/mixed; boundary="----------=_1711458197-2187104-0"
To: my.name@my.domain
Content-Transfer-Encoding: binary
X-RT-Dashboard-ID: 115
X-RT-Dashboard-Subscription-ID: 122
Precedence: bulk
From: rt.address@my.domain
MIME-Version: 1.0

This is a multi-part message in MIME format...

So I presume that RT is adding the Sender header, isn’t it? How can I set it’s value?

X Files…

I’ve tested right now the following steps:

  1. Set $MailCommand = testfile
  2. Set $SendmailArguments = -oi -ODeliveryMode=b -OErrorMode=m -fmy.name@my.domain
  3. Send a test email in Dashboard subscription
  4. I’ve seen RT complains about the -f option in $SendmailArguments.
  5. Set to the previous value $SendmailArguments = -oi -ODeliveryMode=b -OErrorMode=m
  6. Set $MailCommand = sendmailpipe
  7. Test again… surprisingly, the mail is sent.
  8. Checking the SMTP headers… the “Sender:” header is gone.

I can’t figure out what has happened, but it’s working now.