mail relay

I have a question regarding mail relay, is the emails that are “relayed” to another email address and to another mail server scanned for spam and virus before they are relayed ?

Thank You
Best regards


My understanding is that if you do this at the Virtualmin level, then the email is NOT scanned for spam & viruses. But if you do it at the Usermin level, then it is.

An important issue is whether the email header “return path” gets altered by the forwarding process. In the former it doesn’t, but in the latter it does. GMail recommend you always forward without altering the ‘return path’ so that the reputation of your IP address does not get tainted by spam - which makes sense really.

I recently found out that not everyone is that switched on though. Microsoft now run a blacklist for hosted Exchange email. This blacklist seems to be too stupid to understand the “true” sender in the email headers. So here’s the Catch-22: If you forward email the way GMail wants you to, you risk being blacklisted by Microsoft. But if you filter first, and spam still gets through (and it most probably will), then you risk the wrath of Google!

Hi, thank You for reply.

can You please explain what You mean at “Virtualmin” level and “Usermin” level ? I am creating "virtual servers within Virtualmin and the email users, and aliases are created as well …

regarding the explanation for Gmail and MS I know about these issues, we are using iRedMail solution from on couple of servers and I am forwarding a lot of the domains there which are first scanned and than forwarded, but our ip address or domain are not on the black list… sending the emails to many private companies that uses hosted MS exchange and gmail accounts and it works just fine… no emails are being blocked at all…

iRedMail is very nice complete email solution that uses open source server apps such as dovecot, postfix, spamassassin, amavisd etc… therefore I was asking about relayed domains in Virtualmin…

Thank You again !

  1. Virtualmin >> select server >> edit users >> select user >> mail forwarding settings. = No spam filtering I reckon!

  2. Forward + filter: Webmail (or Virtualmin >> select server >> edit users >> select user >> login to Usermin). Then select “usermin >> mail >> filter & forward email” (this latter assumes you have webmin >> webmin config >> usermin>> available modules >> filter & forward email" enabled)

(To be honest - I haven’t tested this. I think you can both filter & forward with this option - but you’ll have to test & see!)

thank You for such a detailed explanation.
I have now logged in as an user in Usermin, but when I clicked on the “Mail” - “Filter and forward” I got the message on the top of the screen:

Warning - The system is configured to not process user-defined mail filters. Filters defined here will not be used.

any plugins that needs to be enabled/installed perhaps ?

At vm >> email messages >> spam & AV, do you have “Allow mailbox users to create mail filters” enabled?

it`s disabled, now I understand the rest…

Thank You very much again for helping !