Added SMTP email support

[shafiq-muhammad]

Adding the support for SMTP email support

[curita]

Hi @shafiq-muhammad!

Some considerations:

1. The CI build for Python 3.9, those errors should be fixed

2. About adding tests, I found there's a flag debug that can be sent to MailSender() so no actual messages are sent (reference). This is used in Scrapy's tests with a callback to catch the message (reference). Maybe that's something we could replicate to add tests for the new SendSmtpEmail()?

   We could add a debug argument to SendSmtpEmail.__init__() or SendSmtpEmail.send_message(), and then pass that flag to MailSender(). We don't need to test MailSender() much as that's already handled by Scrapy, we can focus here on making sure we are instantiating it correctly and calling its send method as expected, and that the message gets "delivered", by using that callback or capturing the debug log messages.

Let me know if that helps and ping me for anything else I can assist you with!

[curita]

I've been checking and the CI started failing because Sphinx's version isn't pinned in setup.py (docs section), and the latest version 5.0.0 requires that language variable to be set apparently.

We could pin it (though ideally, the version requirements in setup.py should be as loose as possible), but it seems better to support it instead if the only thing preventing us from doing so is that variable.

@shafiq-muhammad Could you send a separate PR with the language change? We can merge that one right away. These changes should be enough for docs/source/conf.py:

-language = None
+language = "en"

After it gets merged to master you can rebase changes here to get rid of the CI errors.

[rennerocha]

@shafiq-muhammad Sphinx build problem was fixed in https://github.com/scrapinghub/spidermon/pull/347 . Please rebase your branch so the CI checks will work properly.

[codecov[bot]]

Codecov Report

Merging #345 (1751238) into master (b7b4e0e) will increase coverage by 0.24%. The diff coverage is 96.87%.

@@            Coverage Diff             @@
##           master     #345      +/-   ##
==========================================
+ Coverage   74.03%   74.28%   +0.24%     
==========================================
  Files          72       73       +1     
  Lines        3096     3126      +30     
  Branches      483      487       +4     
==========================================
+ Hits         2292     2322      +30     
  Misses        737      737              
  Partials       67       67              

Impacted Files	Coverage Δ
spidermon/contrib/actions/email/ses.py	0.00% <0.00%> (ø)
spidermon/contrib/actions/email/__init__.py	67.39% <100.00%> (ø)
spidermon/contrib/actions/email/smtp.py	100.00% <100.00%> (ø)

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[rennerocha]

This PR solves #337

[curita]

@rennerocha hi! :) I see you have continued this PR, thank you for your help! Is there anything missing here that we can help with?

[rennerocha]

Hi @curita ! Yes, I am trying to finish this PR so we can have a new release of Spidermon (I need some new features!). I added a few more settings options (that are available in Scrapy MailSender class) and added the documentation. It is only missing an update on the tests (current tests are testing MailSender, not the action). I should be finishing this by this week.

[curita]

Thank you for the update and your work here again 🙇‍♀️ Sounds good then, if you need any help let us know!