[Koha] Overdue notices sent to a random patron (3.16)

[Yuval Hager]

Hi,

I just upgraded to Koha 3.16 using the Debian repo on Thursday. Everything went
fine and was working well.

On Friday, I found out that a patron received 51 emails of advanced due notices
of other patrons. I confirmed this with the server mail logs, but I have no
idea why this happened.

I verified that this patron's email address only shows up under their record on
the borrowers table.

Checking the email logs, it seems that it sends a bunch of emails to a single
patron, then another bunch to another (I don't know what the content is), so
I'm suspecting something strange is going on.

I tried running the overdue_notices.pl script with -n -v, and it just spit out
a list of messages to be sent, but not the email address it would send it to.

Any ideas where to begin searching to investigate this?

Thanks,

--yuval