[gdal-dev] GDAL mailing list email delays

[Greg Troxel]

Daniel Evans via gdal-dev <gdal-dev at lists.osgeo.org> writes:

> Tom's initial email was delayed by 48 minutes, arriving at 1715 UTC:
> - Originally sent by the mailing list at 1627 UTC
> - After a few internal hops, received by lists.osgeo.org at 1636 UTC (with
> a header stating X-Greylist: delayed by 473 seconds)
> - Received my email provider's servers at 1715 UTC
>
> Even's reply was rather speedier, arriving at 1705 UTC, ten minutes before
> the email it was replying to:
> - Originally sent by the mailing list at 1705
> - Received by lists.osgeo.org at 1705
> - Received by my email provider at 1705

I have not noticed.  For your message, the total delay between google
receiving your mail and my server receiving it was 6 seconds.

Many sites operate "greylisting" intended to reduce spam, which is the
practice of deferring mail delivery on the first attempt, and then
inserting a database entry of (delivering-IP-address, sender, recipient,
t) and then when a matching delivery attempt happens at >=t it is
accepted.  Typically a different entry is then made, allowing that tuple
for some period of time like 30 days.

Normally one uses DNS-based databases to skip greylisting on known
legitimate mailers.

Your description matches a theory that your receiving MTA implements
greylisting.   You didn't name your provider, and you're sending from
gmail now.

The way to debug this is to look at the logs at the computer that
receives your mail from lists.osgeo.org, and to see if it is
implementing greylisting.  Only if it is known that there are no timely
delivery attempts is it reasonable to inquire of ilsts.osgeo.org.