Gmail Sync Performance

With so many people on Gmail, we wanted to see how the new Outlook ran with it. For the most part, we saw significant speed improvements — 2x or more — for Outlook 2016 over Outlook 2011.

We should pause here to note that testing and working with Gmail was more than a little challenge. Google regularly throttles performance, and does so at low enough usage levels that impact power email users using any external client. This is why migrating to Gmail with a lot of folders is so hard, and time consuming. The following tests are the best-case scenario we found with Gmail, when (we believe) that Google was not throttling our accounts.

Furthermore, Gmail’s implementation of IMAP is non-standard. And, regardless of email client, you may find that Gmail won’t always show you the correct counts for mail messages. This is not the fault of the email client, but Gmail’s implementation of IMAP.

When you have so many different examples running side by side, you see things from a different perspective — sometimes quite clearly. While it was not part of our goals in this article, and it’s not benchmarking at all, we can tell you that hands down, the experience with Office 365 hosted exchange accounts was far more reliable, consistent, and predictable than the experience with Gmail performance with non-standard IMAP, performance throttling, and sync inconsistencies. We don’t believe these issues appear in Gmail’s web interface, but they do apply to any email application sending and receiving through a Gmail account.


Figure 14: Sync Performance — Gmail Account
(shorter is faster)