I did this and again after it fully synced, we keep having the same issue.

It often displays that several 1000 messages are being downloaded.

Appears to be some sort of sync issue but it is using a lot of memory and causing the computer to run slower.

Did a bit of internet searching and have noted the same problem stated by others but the limited fixes either dont work or the prescribed steps are not available to me ().

Neither Apple nor G Suite (email provider) support was able to offer any meaningful solution.

Outlook 15.40 Mac And Restarting

Changing this to store drafts on my mac and restarting Mail resolved the issue for me.

I hope this is useful to others suffering from this issue, of which there seems to be many.

Im not sure if this is an issue with G Suite or with Mail, or maybe a combination of both.

Interestingly personal gmail accounts dont seem to be affected.

Regardless it was incredibly frustrating to deal with considering email working properly is one of my most basic expectations from my computeremail provider.

This seems to have fixed the constantly downloading issue for me.

I reported this to Apple on the 4th of December 2017, and after speaking with many support staff at Apple Care, we still as of today (23 Jan 2018) dont have a solution.

For us, its having a financial impact as we are going over our data allowance as we are using wireless 4G in our office, and in Australia, these are limited.

Plus its cost us the time we have spent trying to fix the issue with Apple.

Outlook 15.40 How To Fix It

The issue is, Apple doesnt know how to fix it, otherwise, we wouldnt be here talking about it almost 2 months later.

I then discussed this with Google and they said that it cant be and gave me a number of reasons why it isnt their issue.

The one thing that they told me to do to isolate the problem was to use the same accounts on a different mail client, and if the problem did exist after doing that, then perhaps the issue may be with Gmail and the settings.

So I did the exercise and put all the accounts into Outlook for Mac.

After spending about 24 hours syncing across all accounts, Outlook was stable.

I then had both mail clients running for a few days and took screenshots of the activity monitor to show how much data was being used by each program.

This proved the issue was with Apple Mail and not with Gmail.

After doing all this, I was told to delete all accounts from Apple Mail and to reinstall them manually (without the Google prefixed settings).

Download Outlook For Mac 15.40