I guess I just need a point the right direction or a suggestion of a particular function or tutorial so I don’t spend hours trying to do something that isn’t possible to do in the first place.

My plan is to write a pre-processing script that will split up the main mail log file into several files based on the sender email address.

Why? Did you hit any boundaries with pflogsumm? Is splitting even necessary?

Splitting up a mail log file is tricky, since the sender (envelope) address isn't the reference for log entries, afaik. Each mail gets assigned a message ID, and depending on the mailer, a processing identifier which might change through the delivery chain, depending on setup. If you have e.g. a sandwich setup, postfix delivering to spamassassin and a virus checker, then picking up the message again with a second instance of postfix, the internal IDs will likely change; you would then have to take that into account. Having all that done and producing a set of output files suitable for pflogsumm, you will have either rewritten or duplicated a large part of pflogsumm itself.

Since you didn't mention any constraints of your setup yet (processing speed? memory? disk space?) but only spoke of your plan, more information is needed to give good advice. What has been the outcome of using pflogsumm "as-is" so far?

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