Problems using python3.7.3 and sendmail 8.15.2 (Debian10, Buster)

[wwortel]

Could not get pysrs.py to work. pysrs.py now starts itself under python3. In several places had to make .decode('utf-8') statements because of byte types not being mixable with string types. The socket expects and sends bytes, not strings.
Also when SocketMap.py writes, a final ',' was missing. I attach pysrs.py and SocketMap.py with the adaptations made.
modified_files.zip

[sdgathman]

Testing on python3 is on my todo list.

[sdgathman]

I have a manual testd.py to test the SocketMap server. That needs to become a test case before I do any more fixes .. oh wait, I already did! Let's see if it fails .. it's not failing. Oh, it is testing the Exim compatible server. We don't have a test case for SocketMap server. So that is needed before we fix anything.

[wwortel]

Hi Stuart,
Made it work through trial and error, using some 30 simple emails coming from gmail and going to one live server that forwards it to another live server, both of which I have access to and are identical in terms of OS and sendmail+milters. The normal start of the pysrs.py daemon obfuscates the error messages so started manually all the time to have errors show up on the console once the email to be forwared was being received. That pointed to all the problems, nearly always related to type issues.
The mail and syslog log files are not so helpful as sendmail just stops processing and gives a 'data format error'.
The corrected software now is installed on both servers and I have tested that the first properly adapts SPF and the second recognizes it as forwarded from an SPF authorized IP. It is quite possible that by making an adaptation elsewhere in the code less changes in total would be needed. I just was guided by the type errors as they popped up and then made the types fit.
The last error, before the whole chain working, was the complaint about a ',' missing. I just added that to the bytes sent and it made the error disappear and the email being processed properly on the sending and receiving server.
The messages received from Sendmail as part of the From: information contain non utf-8 compatible bytes; in particular the 0x9b that separates elements of the address as given by Sendmai. So until those have been removed all action needs to be bytes based and not string.

[sdgathman]

I added a test case that runs pysrs.py as a subprocess and makes map requests to it. Haven't tested in a live py3 email system yet.

[sdgathman]

I will work on packaging for Fedora/EPEL