SMTP Whitelisted Inbound Domains still slow to pass emails to mail server

[mylesw]

I'm not exactly sure what my expectations should be here, but I have setup a PMG in front of our mail server, and all is working fine for bi-direction integration. The one thing that caught me off guard was the time delay that was occurring between receiving a legitimate email from an external source, and seeing it appearing in the mail server. My initial attempts were taking up to 30 minutes before we saw the email.

I have scoured the documentation, forums, etc. to learn about the power of the SMTP Whitelist, so I put the domain in there, adjusted all the Spam scoring to ensure that the email was not being quarantined, and they are flowing through now. But even with this, there is still a 2-3 minute delay between them coming in and arriving in the mailbox.

This may be quite an acceptable delay, but just so I can manage my (and my client's ) expectations, what should the delay time be on whitelisted emails through PMG? Is this a normal time period to expect, or should I keep digging through settings to optimize this further?

Thanks
Myles

 

[hata_ph]

Pls show the pmg log

 

[mylesw]

Actually I think I have resolved the issue. It was not a problem on the PMG side - after I managed to find the live logs and ran it alongside the live logs of our mail server (tail -f /var/log/mail.log), I could see in real time the flow, and that showed me that PMG is super fast at processing them. The issue was on the receiving end (our mail server), and the communications between PMG and it was flawed. I fixed that, and now everything is flowing at lightning speed.

I suspect you guys get a bit of this - since the first point of contact for email is PMG, problems that lurk behind it often don't appear for what they are, and appear like it is a PMG problem. I can attest that this has been my experience, yet the issue had nothing to do with PMG. I would encourage others that face similar situations to do live log analysis in real time for BOTH PMG and the mail server to help resolve it, and then the issue can be directed to the right system.

So I'm resolved here. Not sure how to mark this as "SOLVED" but feel free to do so.

Thanks
Myles

 

[hata_ph]

Could be greylisting on your internal mail server side?

 

[mylesw]

Could be greylisting on your internal mail server side?

That's exactly what it was. I thought it was the greylisting in PMG, even though I had SMTP whitelisted the domains. I thought that the whitelisting wasn't working. Of course it was working. The problem was that the receiving mail server wanted to do redundant things like SPF checking, greylisting, etc. and that needed to be turned off since PMG was doing it all.

What I noticed and probably could be done better in a tutorial was to show not just how PMG works, and how to set it up, but how it should be used in conjunction with other mail servers, and specifically what you need to disable on the mail servers because PMG is doing it. That might seem obvious to most, but when you are in the weeds with the settings, it is really easy to forget the design architecture and what needs to be done outside of PMG.

Anyway it is all working now, but has been an interesting (and rewarding) experience.

Myles