We have had ongoing problems with delivery to the kcm.co.zm (Konkola Copper Mines) domain since time immemorial. Konkola appears to host their own mail server over a very slow Zamtel connection. This means their connection appears to be extremely limited in what it can handle. While sporadic small emails without attachments generally go through within a day or two (yes, that’s days, not seconds, minutes or even hours), larger emails with attachments either stall or take so long to deliver that they affect delivery of other emails.
That is the case today. Three large emails from two clients to over one hundred kcm.co.zm email addresses effectively plugged up the mail server while it waited for the kcm.co.zm mail server to accept delivery, preventing delivery of hundreds of other emails. We had no choice but to delete these emails. As soon as we did, the backlog of several hundred emails that had built up over the course of about an hour were successfully delivered within minutes.
If you email people on the kcm.co.zm domain, please consider reducing the sizes of attachments and reducing the number of kcm.co.zm email addresses you include in your distribution lists. You might also want to point them to this post so that they might become aware of the problem and therefore do something to fix it.
