Sendmail SMTP connection very slow

[Eric33]

Hi All,

I am a newbie to sendmail and need some help.

Currently, connections to the sendmail (8.14.3) SMTP port is very slow.

I have already set Ident Timeout to 0.

My observation is that the slowness is due to sendmail performing a reverse/forward DNS lookup on the source IP of the connection, and the source IP is not resolvable.

Is there any way we can disable the reverse/ forward lookup on sendmail? In my case, setting a private DNS or Host file is not practical, as there are many possible source IPs and they are not fixed.

Thanks a lot.
Eric

 

[normntwrk]

you could try this
FEATURE(`accept_unresolvable_domains')dnl

 

[xernet]

Hello
I have this matter too..
My ISP is very slow to fix my reverse DNS..
I asked them 2 weeks ago :-(


Anyway, i have tryied your suggestion, but it still doesn't work,

A SMTP REPLY after CONNECT (client log) is about 29/34 seconds...

confTO_IDENT doesn't solve the matter too, default is 5 sec...

a reverse DNS will fix this trouble?

if yes, the hostname to provide to the ISP (ip's isp), it's important and must be the same wrote in /etc/rc.conf ? (FreeBSD)
i mean the real HOSTNAME? or it does not matter?
(that's why i have multiple domains in that server)

thanx in advance for your responce