Sierra Mail Slow

Since the update to Sierra, my mac mail is a disaster too. Emails are not searchable. I type in the email of the person I sent the email to at the top search bar and get nothing and have to dig and dig until I find the email buried in other emails for some stupid reason. It doesn't even show up as it's own sent mail for whatever reason.

Emails hardly ever load on the right viewing window. Just blank white space. Even though, I can still see the first beginnings of text on the left preview side.

Everything is slow and doesn't reorganize properly the way I have set it up. I use Mac mail for business and NEED the ability to have emails auto copy into other folders. And you know... being able to actually SEE the emails is kind of a plus for business purposes as well.

It works alright for gmail, but I have a professional domain hosted through Bell and Mac Mail apparently has various issues with certificates for this as well.

I never had an issue with Outlook when I've used PCs... may have to switch back. Apple should seriously consider their growing business base and fix the absolute FUBAR situation of mac mail that's going on right now.

So far, I actually think this may have worked for me... but I find Mail always runs a bit quicker after a restart so I will let you know with an update. But man, if you've fixed my issues... I sort of want to bake you cookies. This has been driving me nuts for weeks.

I'm having terrible problems with Mail and Photos since I upgraded to High Sierra this past month (to read TurboTax DVD - probably a mistake. Trying all the fixes mentioned here, including yours. However, I don't see where "Download Attachments" is located within Mail Preferences? What am I missing? Thanks, David

I have a similar issue post-Sierra upgrade

Some Mail messages load quickly, others take minutes, whether they are large or small. Can't find any pattern.

In Mail, go to the Mailbox menu item >> click Rebuild. This will reindex the mailbox, and this should speed things up once it is complete.

Re-indexing has not improved the situation at all after a couple days. Is it possible the re-indexing is not complete? My mail workflow is causing extreme frustration at my end as it is affecting my work productivity. The one thing I'm certain is that it was working correctly prior to Sierra updated. Thanks for any help.

Same problem for me. I tried different recommended solutions, but none of them did help. Mail is very, very slow after upgrading to Sierra. Not amused.

I am seeing the same thing. This is on a mid-2015 MacBook Pro. I've tried rebuilding mailboxes and it hasn't helped. I posted about this a few days ago and I am relieved to see that I am not the only seeing this.

Same issue on my end - close to fully unusable on a MacBook of end 2015 - Apple, any fix?

Rebuild etc not working. I also did a clean install - performance was good for 4-6 hours - now back at the same level when I "just" upgraded. Of course all third party plugins disabled.

Rebuilding does not particularly help. This is awful, I hope Apple can fix it soon.

Has anyone who has access tried the 10.12.1 beta to see if that solves the problem?

I have the same issue. Any of my digitally signed email takes literally minutes to open - this is the bulk of my work email. It also takes minutes to send a digitally signed email.

My unsigned email in and out are fine.

I'm having the same issue with my 2014 MacBook Pro and 2014 Mini. Reindexing didn't do much to help.