Add ForwardAsMime setting to control the default forwarding behavior

[emreyolcu]

MailFlow forwards messages as MIME attachments by default and inline if the Option key is held down. I added the option ForwardAsMime to allow changing the default forwarding behavior. The option is on by default, which preserves the current MailFlow behavior. Setting it to false causes messages to be forwarded inline by default and as MIME attachments if the Option key is held down.

[arachsys]

Hi. Do you have MailFlow working on up-to-date macOS, i.e. Ventura or later, given this pull request? To be honest, I've not been actively maintaining MailFlow and MailWrap as my understanding is that many of the APIs they use changed in Ventura, then the plugin API itself was yanked in macOS Sonoma last year. I don't have a modern Mac to be able to test easily either. But maybe I'm incorrect about the status of Mail.app plugins and they didn't kill plugins after all?

[emreyolcu]

Big Sur (11.0) broke a few things that I use daily, and I think macOS mostly degraded in quality after Catalina (10.15), so I am staying on Catalina. I had previously hardcoded the changes in this pull request and my other one (#6) in my local copy of this repository that was at fa16b3d. I can only confirm that, given the changes in the two pull requests applied on top of fa16b3d, MailFlow works on Catalina. Before creating the requests, I pulled the more recent changes and assumed that nothing was broken in between. It turns out I was wrong. For me, 870af85 breaks MailFlow. My changes are orthogonal to the breaking change, so there should not be any harm in merging them if you wish to do so. However, given that I cannot confirm that the current master works, feel free to close the requests without merging. I have rolled my local copy back to fa16b3d.

EDIT: It seems that 870af85 breaks MailFlow for me due to some Python configuration issue. I will see if I can figure out what is happening.

LATER EDIT: My issue was due to a discrepancy between system and user Python. After accounting for that, I can confirm that MailFlow works on Catalina given this pull request (and #6).

[arachsys]

Thanks for the updates on compatibility with the latest release. Am I right in thinking it now works fine with python2 and python3 on Catalina? I tried quite hard to make sure I didn't break anything on either python2 or python3 on the older versions of Mail.app while updating support for the newer versions. I was puzzling a bit over what I might have got wrong!

PS I'm not averse to adding some more configuration options like this to MailFlow and MailWrap, but it might take a few days for me to borrow a mac so I can properly test them before pulling any changes.

[emreyolcu]

Am I right in thinking it now works fine with python2 and python3 on Catalina?

That is correct. (Previously, I was installing using not the Python 3 available in /usr/bin but one that I had installed using conda, and that was the problem. I did not run into any issues before Python 3 support was added, because the Python 2 in /usr/bin is the only one I have.)

PS I'm not averse to adding some more configuration options like this to MailFlow and MailWrap, but it might take a few days for me to borrow a mac so I can properly test them before pulling any changes.

Sounds good!