[quote user="EduaRT"]In MercuryS SMTP Server --> Connection Control, I checked "Only Authenticated SMTP connections may relay mail" but this obviously only applies for non-local users. How can I force local users to SMTP authenticate first?[/quote]

The operative part of that option is RELAY, and it does force local users to authenticate prior to RELAYING mail TO non-local addresses.

You cannot require authentication for mail addressed TO local users, or else how would foreign servers deliver incoming mail?

You could probably set it up like this if you want, but you would need another instance of Mercury with a different local-domain to be the SMTP server, and deny access from the local network to the SMTP server on the "local" Mercury.

You can run two instances on the same machine, from different directories, but you can't have conflicting services running on the same ports.

Hello dear

community,

This is my

first posting here - I already spent lots of hours searching google and didn't

come up with a solution, maybe one of you can help me. I want to use Mercury

Mail as a mail server in a local network. I managed to set up everything and I

am able to send mails from one client to another in this local network via the Mercury

Mail server. The whole environment is set up locally, i.e. communication is

only between local users and not with the outside world (internet).

What I want

now: When a local user sends a mail to another local user, I want them to SMTP authenticate

first. At the moment, any local user can use the mail server without authentication

if the mail is directed to another local user - talking about telnet for

example, is there a possibility to set up a mandatory AUTH LOGIN for every user

before sending (local) mails?

Thanks a

lot for your help!

> What I want now: When a local user sends a mail to another local user,
> I want them to SMTP authenticate first. At the moment, any local user
> can use the mail server without authentication if the mail is directed
> to another local user - talking about telnet for example, is there a
> possibility to set up a mandatory AUTH LOGIN for every user before
> sending (local) mails?

You can turn it on but there is no requirement in the SMTP protocol for a sending server to authenticate when delivering mail to a local account.  This is the way it has to be since thee is not way a foreign server will be able to authenticate.

What you can do though is turn on SSL/TLS and require your users to use this type of connection.  This way only SSL/TLS type connections are accepted.  You should then block the user of port 25 so that normal server deliveries are blocked.

Hello Thomas,

thanks a lot for your quick response! Actually, I'd like to test the first alternative - Turning on SMTP authentication for all users - but I havn't found the settings for it in Mercury. In MercuryS SMTP Server --> Connection Control, I checked "Only Authenticated SMTP connections may relay mail" but this obviously only applies for non-local users. How can I force local users to SMTP authenticate first?

Thanks a lot,

Eduard