# Sendmail problem over GRE tunnel



## hgeorgiev (Dec 21, 2013)

Hello. I have two FreeBSD routers (8.0 and 9.2) in different offices and IP-IP tunnel between them. Each have sendmail which working fine standalone, but for one domain sendmail must redirect mail from one to another sendmail over internal ip address ( tunnel). And here is a problem....I get timeout. I seek for solution over a month . (of course I have telnet on port 25 between sendmails over tunnel)
 Today I get Mikrotik, replace one FreeBSD, make MSS Clamp....same problem. All other services work fine between tunnel (share, www,....)
I try GRE and GIF 

If someone have other idea.....


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## junovitch@ (Dec 22, 2013)

Hello.  If I understand correctly you can telnet to port 25 and see the Sendmail banner but Sendmail doesn't actually work.  Remember that Sendmail does a lot of DNS checks when it comes to dealing with email.  Do you have proper DNS records for the internal IP addresses that Sendmail uses?


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