Gmail has recently adopted the new security standard OAuth 2.0 and this means that now mailwatch-plugin can't connect to your Gmail account (error 401).
The solutions are reported in this discussion http://stackoverflow.com/questions/25413301/gmail-login-failure-using-python-and-imaplib, that is:
1) you choose to allow the access for less secure apps https://www.google.com/settings/security/lesssecureapps;
2) mailwatch-plugin implements the OAuth 2.0 protocol (better solution)
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This bug has been migrated to xfce.org's GitLab instance and has been closed from further activity.
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