> /var/log/maillog shows for example:  Sep 27 14:35:10 pomcoweb
> sendmail[15045]: NOQUEUE: sc015pub.verizon.net [206.46.170.59] did not
> issue MAIL/EXPN/VRFY/ETRN during connection to MTA
> 

This means they connected but did not issue a command.

> this is happening for mail from earthlink, verizon, et al, though not
> everywhere, eg mail from TCLUG is arriving fine.

Just a guess, but if this is for greatlakedata.com, I just tried
connecting to port 25 of mx.greatlakesdata.com and it took considerable
time for the mail server to respond with the SMTP banner.  These places
that are not able to deliver might just be getting impatient and closing
the connection before your server responds.  Sendmail defaults to 5
minute timeouts on many of these things, and (again just guessing) it took
more than a minute for me to get a response.  But it's entirely possible
some people have tweaked the timeouts (or are using an MTA with less
patient settings).

You can try yourself (do it from outside of your network...)

telnet mx.greatlakedata.com 25

See if it takes awhile to get the 220.  I tried from two machines on two
different networks and got the same result.

Others will tell you to switch to Postfix or Qmail, but DON'T BELIEVE
THEIR LIES!  (cue anti-sendmail banter...)


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