[exim] SMTP Banner delay of 2 mins 30 seconds

Hello,

Our mailserver (non-Exim..it's Kerio 6.6.2) is experiencing a consistent and
repeatable smtp banner delay when connecting to Exim 4.69 mail servers.
When telnet'ing from our outbound MTA to port 25 on four different Exim 4.69
domains/servers there is a delay of precisely 2 minutes and 30 seconds
before I see the SMTP banner. When I telnet from a different IP address
(same /24 network as the Kerio mail server) to the same four Exim servers, I
receive no delay.

I suspect there is some type of greylisting/antispam going on here, but the
delay seems to be quite excessive. I have checked spamhaus to see if our
server's IP is listed currently, but it is not.

Would you folks know of a reason why Exim build 4.69 would be behaving this
way consistently across four different domains? I have not seen this issue
other than on Exim 4.69 (but I have only seen it today on these four
domains).


Thank You.

-Eric