The following sections only apply when using macOS 13 and earlier with the Mail plug-in setup. The If Apple Mail Is Running Slowly section has information about general Mail slowness problems, as well as slowness related to the Mail extension setup.
Slow Launching of Mail
If Mail is launching slowly (which can cause SpamSieve to deactivate its Mail rule) and you are using macOS 10.14 or later, the slowness is probably caused by a Mail bug. After a Mail plug-in (any plug-in, not just SpamSieve) has been installed for a long time, Mail sometimes pauses before loading it. There are two ways to work around this:
Manual
Deactivate and then reactivate the plug-in:
Go to the Rules tab of Mail’s Settings and uncheck the SpamSieve rule.
Go to the General tab of Mail’s Settings and click on Manage Plug-ins…. Uncheck SpamSieve.mailbundle and restart Mail.
Note: It is important to temporarily disable the plug-in this way, from within Mail, rather than using the Uninstall Plug-In… command, as Mail has access to reset files that SpamSieve cannot access.
Go back to Manage Plug-ins… and check SpamSieve.mailbundle. Now restart Mail again.
Go to the Rules tab of Mail’s Settings and check the SpamSieve rule to make it active again.
This will usually speed up Mail’s launching for several months, if not longer, at which point you may need to repeat the procedure above. If you find that Mail slows down again sooner than that, please let us know.
Automatic (Experimental)
On macOS 13 and with SpamSieve 2.9.52 or later, you can click this link to tell SpamSieve to enable its automatic workaround for this issue. You can also click here to disable the workaround. Please let us know if you encounter any problems.
Hang When Launching Mail
If Mail is not just slow (as above) but does not finishing launching at all (after waiting a few minutes), it may help to: