Issue sending email to certain internal domains using Mailx on REHL version 7

Double_AA · 05-18-2018, 09:35 AM

Internally we have several domains hosted by our exchange server. MailX is configure to relay email through our Exchange server. When sending mail via the Mailx program I can send to 2 of the domains but the other 2 the mail does not go through. I reviewed the Mailx logs and it appears that when sending to the other domains it is referencing incorrect Ip address meaning they for whatever reason it is not looking to the mail server. Any thoughts?

MensaWater · 05-18-2018, 10:50 AM

The MX record for the domain may be incorrect.

Run "dig -t MX <maildomain> to see what it tells you.

Run dig on the MX record if the dig above doesn't give its IP in the Additional Section.

Verify you can access the IP the MX is resolving.

You MIGHT be able to fake it out by adding the MX name to your hosts file with the IP you want if the IP is different.

e.g.
MX:
300 IN A smtp.mailexample.com.
Additional:
smtp.mailexample.com 3600 IN A 192.168.12.1