[SOLVED] Proper SMTP config

[mfehr]

Hi,

I run Zimbra with my own 3 domains since a couple of months. So far, all mail was relayed through the SMTP servers from my ISP. Since this Friday, my ISP does no more allow senders from non-ISP domains to relay through their SMTP server.

Therefore, I sent e-mails straight from Zimbra without relay. Unfortunately, the first e-mail I sent was rejected by the recipient server based on their anti spam defense:

<user@recipient.com>: host xxx.recipient.com[999.999.999.999] said: 550
    5.7.1 <user@recipient.com>... Mail from 99.99.99.99 refused by RBL,
    RSS, or DUL, please see www.mail-abuse.com, sender is sender@sender.com (in
    reply to RCPT TO command)

As my ISP now uses gmail, I tried to relay e-mail through google's smtp server. Mail gets delivered. However, the sender's e-mail address is exchanged with the account used to authenticate. Therefore, any response to such e-mail go back to gmail instead of the origin. Therefore, gmail is not an option.

What is the proper approach to configure Zimbra and other tools so mail is not refused by RBL, RSS or DUL?

Further background:

• I have a dynamic IP address, owned by my ISP
• Mail is mainly processed by local mail clients

[uxbod]

Unfortunately you are going to have this problem with a lot of MTAs due to being on a dynamic IP address. They will certainly check whether your MX record for your domains do match to the external IP address. As your ISP will not allow you to relay through them you may wish to look at a service like this :- DynDNS :: Mailhop Outbound.

[mfehr]

I signed up for this service and it seems to be working. Thanks for the hint!