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SMTP Mail Servers using DDNS - Mail Reputation Issues?

User_3WQV1
User_3WQV1 Member Posts: 2 Green Ribbon

TalkTalk Business managed to lose my /29 RIPE allocation, so I had to move my mail servers on to DDNS in rather a hurry. Actually the process was pretty painless and everything went rather well, however now I'm finding that mail is being rejected by external mail filtering services.

I've been careful to keep the dyn host name in the MX record, so a reverse DNS lookup works. I'm wondering is Mail Handling Services don't like the host resolving to a dyn CNAME as apposed to static address?

I'm interested to know how other people have implemented DDNS for SMTP Relay and avoided having mail rejected (550).

User_XVACU

Comments

  • User_XVACU
    User_XVACU Member Posts: 1 Green Ribbon

    I'm curious how you set this up:

    "I've been careful to keep the dyn host name in the MX record, so a reverse DNS lookup works"

    I cannot find instructions anywhere how to set this up properly on Dyndns.org. Anytime I try to send email to my smtp server (with the dynamic IP address) it bounces with "no MX record found".

    Dyndns.org does not make the setup very obvious.

  • User_3WQV1
    User_3WQV1 Member Posts: 2 Green Ribbon

    So in DNS (3rd party, whoever hosts the Domain) add MX records for the hosts names of the SMTP servers. MX stands for Mail Exchanger. Normally in your Domain DNS editor (hosted by your ISP) there will be a section which says MX. Add two SMTP Servers. You can set peiorities of say 10 and 20 or leave the priority blank. You can check the MX records as follows:I n a command prompt type:

    nslookup

    set q=mx

    yourdomain.com

    You will see the results of the MX lookup query.