Q: Lag in Typing in Yosemite's Mail w/ External Apple Keyboard

i typed gibberish with one hand (including spaces and returns, which seem to exacerbate the lag, at least for me). not scientific, but tried it 3 times and i did not seem to see any lag as long as the cursor was kept in motion (or maybe i'm imagining things). anyone?

If you have Keyboard Maestro, you could try this:

Make a KM macro with Mail as the only scope. Trigger it with a Status Menu item.

Add an Until Action (Control Flow folder)

Set it with two internal actions:

Move Mouse (Just Move) from current position to 10 px.

Move Mouse (Just Move) from current position to -10 px.

(If you want to be creative, you could move the mouse in a square or another shape. Go wild!)

Until This Application > Finder > is at the front.

So this macro will start jiggling the mouse back and forth when you select the trigger from the KM menu. It will stop if you click on the desktop.

You can’t use the mouse for cursor positioning in Mail while this is running, of course.

I wrote a several paragraph e-mail with no type delays while this (annoying) macro was running. OTOH, I only saw one character delay when I typed some with the macro off.

Y'all are just getting goofy now. I gotta unsubscribe from this mess.

you mean we shouldn't try anything, just whine and wait?

I don't think it's goofy to troubleshoot an issue.  I think the mouse movement thing is one of the first things we've been able to reproduce with 100% success.  That's a crucial part in figuring something out.  I'll give you this though, it's not going to be something we can fix.  This is in Apple's court.  I've logged this into the bug so perhaps it will help Apple troubleshoot to know that this makes the problem disappear so reliably.  But hey, ta ta!

I think the mouse movement thing is one of the first things we've been able to reproduce with 100% success.

How many users? For how long?

Like I said, when I just typed a few minutes ago, I only saw one minor delay. This is an annoyingly intermittent bug.

Nevertheless, thanks for keeping your bug report up to date.

I had a 2-year old iMac in which I upgraded the operating system to Mavericks and soon after, Mail fell apart - apparently because our company uses an exchange server (though we used the same mail server pre-update).  My mail folders would disappear — as I watched them, though if I deleted the account and reset it, they'd come back.  Our Mac tech urged me to use Outlook, which I did in protest, simply to keep working. Then, in December, I bought the new iMac and had our tech do a completely clean install on Yosemite.  Every single bit of software installed separately, and every preference re-entered.  Mail worked well for two weeks.  Then the lag started, which makes typing next to impossible in Mail, and since we are a client-based business, I spend about half my day in email.  So, I closed mail and re-opened Outlook, and it all works.  Honestly, I just hate using Outlook.  But I hate having Mail malfunction even more.  And by the way...changing to Helvetica Neue did not change a thing.  (I suppose I can at least find comfort in the fact that my mail folders didn't disappear.)

Yet another beta released, focus on wi-fi and MAIL....:

http://www.macrumors.com/2015/01/14/apple-seeds-10-10-2-build-14c99d-to-develope rs/

there ARE other mail apps; i just downloaded Postbox...which i may (or may not) try...

Dear All I have try to uncheck the "correct spelling automatically" and the lagged is gone. Please try and update. Thank you.

IIn my experience, that will not solve the problem. Just give you a false sense that it's solved like many other fixes that have been tried. But please report back if the problem does not reappear for you after some time.

not a fix here...

it froze.

so i wiped out the hd, installed yosemite from scratch.

then in "migrated" my stuff using migration assistant from a back up.

it seems to have cured the lag.

i say this optimistically bc the lag may be hiding behind the next word i type but...

OK, just to recap.  A few things, in combination, have dramatically improved (but not completely eliminated) the problem for me.  Those are:

- System Preferences: turn off handoff (System Preferences -> General -> "Allow Handoff between this Mac and your iCloud devices"

- System Preferences: turn off smartquotes and dashes (System Preferences -> Keyboard -> Text -> "Use smart quotes and dashes"

- Mail.app Preferences: turn off auto detect and maintain account settings in each email account (Mail Preferences -> Accounts -> Advanced -> "Automatically detect and maintain account settings")

I'm noticing one other thing that I'd like to add to the pile -- a possible memory leak.  I am composing a reply to a message and I've left it open while researching the lag issue.  I'm watching Mail slowly ratchet it's memory consumption up from about 100 mB to 825 mB in the half hour that I've been researching.  So I'm wondering if others are seeing the memory leak as well.  Here's what I can report about the memory leak:

- It appears to increment at about 100k per second, very regular clock-like behavior

- It only happens when I am composing replies, it stops when I send the reply

- Mail doesn't reclaim the memory after the reply has been sent

I'm thinking that we're experiencing an interaction/combination type problem.  I finally sent the reply (people were waiting for it) but I bet if I'd left it open, it would have eventually consumed a large proportion of memory on my machine which would have introduced a whole bunch of bad behaviors accompanied by spinning beach balls.  So I'll be restarting Mail in just a second to clear that memory.  And I'll also be using a text-editor to compose replies rather than the editor in Mail (so's to slow down the memory leak by having replies only open for a few seconds rather than half an hour or more).

For now, those three settings and periodic Mail-restarts have helped.  Like others I'm experiencing the "cursor jump back to the previous line" problem while typing this post.  As Sherlock Holmes would have said "this is a two-pipe problem Dr. Watson"

am wondering if it could be an issue with corrupted fonts. yosemite seems very unforgiving of this. maybe...

one of the things that made my 2nd attempt to migrate to a clean install work was the deletion of a font management program & the removal of all associated fonts. (i copied them to an ext hard drive until i find another font management program i can afford & work with)