When does autodiscover run?

Question

In investigating a problem, I'm trying to understand when a phone, iPad or mac sends an autodiscover request to my_domain.com/autodiscover/autodiscover.xml. This is for Office 365.

Specifically,

1. Does autodiscover run automatically at certain frequencies or only after certain events such as sending or receiving email?
2. If my device is locked because I left my computer for a few minutes and the screensaver is on, but computer is still running, could autodiscover run?
3. If my device is sleeping but I start to log back in, would autodiscover run or would I need to be logged in first?
4. Any other odd times that autodiscover would run?

Answer 1

I believe autodiscover requests kick in:

1. When a user account is configured or updated
2. When network connections change
3. When the client polls the web services for changes.

I believe the default polling period is an hour. That seems to be backed up here in this article For Outlook 2016 on Mac. https://technet.microsoft.com/en-us/library/jj984202(v=office.16).aspx

This article also states

1. Polled every time Outlook starts
2. if mailbox is moved on backend - I believe this get's triggered from a response the server sends to tell the client it need to redirect, which triggers an autodiscover request.

There are a lot of other variables to determine when your device is polling the service. When it sleeps if it shuts down the network port - then when it resumes, I would think this would trigger a request. But if the NIC is not configured to powerdown, this may not trigger it.

I could not find any other specific information for the iphone or ipad or general ActiveSync connections. My own knowledge of this goes about as far as you reading here - but I hope it helps.