Fix Microsoft 365 SMTP auth

[ca-leet]

• added custom login auth
• resolves '504 5.7.4 Unrecognized authentication type' error with Exchange Online
• PlainAuth hostname validation incompatible with O365 cert names

[craig-morris]

Please I'm having this issue. What do I do?

go: downloading github.com/gobwas/pool v0.2.1
go: downloading github.com/gobwas/httphead v0.1.0
fork/exec /tmp/go-build3575759606/b001/exe/main: exec format error
make: *** [Makefile:2: test-darwin-arm64] Error 1

[ca-leet]

Please I'm having this issue. What do I do?

go: downloading github.com/gobwas/pool v0.2.1 go: downloading github.com/gobwas/httphead v0.1.0 fork/exec /tmp/go-build3575759606/b001/exe/main: exec format error make: *** [Makefile:2: test-darwin-arm64] Error 1

Please try cloning the repository using git and building with go:

1. git clone https://github.com/ca-leet/squarephish2.git
2. cd squarephish2
3. go build -o squarephish ./cmd/squarephish/

[craig-morris]

Thanks @ca-leet Please how do I use the config.json file I seem to be having issues with binding. I am using a VPS machine.

[craig-morris]

FATA[2026-01-11 15:06:28] error starting dashboard: failed to start dashboard: listen tcp x.x.x.x bind: cannot assign requested address

[0xZDH]

The idea behind the PR looks good to me, but there are a few concerns that I would like to address prior to merging:

1. The diff itself is quite noisy as a result of changing the formatting between tabs to spaces (likely due to a local editor). If you can update the PR to revert all of the format changes as seen in the diff, that would be awesome.

2. While LoginAuth might resolve O365 issues, this solution completely removes the PlainAuth option. I would prefer to not remove one in favor of the other and it seems like there are several solutions where both authentication types are implemented via fallbacks (e.g. See the following gist comment as an example: https://gist.github.com/andelf/5118732?permalink_comment_id=4825669#gistcomment-4825669)

3. The 'default' mechanism in the LoginAuth Next function returns the username, but perhaps - based on existing implementations - it might be better served to return nil and raise an error when an unknown response from the server is seen/being handled.

See the following GitHub Gists for reference:
https://gist.github.com/andelf/5118732
https://gist.github.com/homme/22b457eb054a07e7b2fb