What does "Allow to send as" do? In my tests it does nothing..

saibotma

I have two mailboxes in my Mailcow: one@example.com and two@example.com. In both, the ‘Allow to send as’ setting is configured with their respective addresses.

However, despite this configuration, I can still send an email from my mail program using the mailbox of one@example.com with the sender address set as two@example.com.

Is there a way to prevent this, and what role does the ‘Allow to send as’ setting play in this scenario?

esackbauer

I get an error message if I try this in Thunderbird.

What is you mail program? And how did you configure your smtp connection? Port 465 or 587?
Seems like you whitelisted too much…

saibotma

Using Spark on Mac. SMTP did autoconfigure and there is no way to see the settings in Spark, unfortunately.
You are right, though. It works when using the default Mac Mail program.

When sending a mail using Mac Mail, then the Return-Path gets set to the alias, correctly.
When sending with Spark, then the Return-Path gets set to the address of the sender mailbox.
Both set the From header to the alias.

Spark is probably just adjusting the From header and thus not really using the alias to send the mail.
So Spark really needs to fix this…