iPhones cannot send and receive e-mail without Wifi

[Anonymous]

We have been battling this out with O2, Apple and our IT department for 11 months but noone is able to resolve why none of our iPhones (6, 7, and SE) can access e-mail when not connected to wifi, and everyone blames the other party. I am now hoping there is a tech brain out there who can offer suggestions!! Data is activated, e-mail accounts have been reinstalled numerous times (off wifi). iPhone software is up to date.

[adamtemp64]

What server settings are being used as o2 no longer runs email servers for consumers etc (that had to be used) 

There has to be a configuration issue . 

[Anonymous]

Our IT guys say it's an exchange server

[jezza1234]

Have you checked in your email settings to ensure that email is allowed to access mobile data?

Settings---mail- --allow email to access (make sure the mobile data slider is showing green)

Might be something that you've already checked and is obvious and simple. But sometimes its the obvious and simple thats the problem

Spoiler

[Anonymous]

Thanks, yeah we have; in mail, in data, in settings, in accounts. Apple say it's not the devices, O2 say it's not the lines, our IT department say it's not the exchange settings...

[jezza1234]

Im assuming that you are able to access email via the web bowser over Mobile Data. If so then the issue clealry lies in your mail server settings, probably a port issue. Exchange servers are the worst unfortuantely when it comes to IOS. which is why we all now use Gmail as our mail server and have no further issues even when accessing via IOS. 

[adamtemp64]

@Anonymous I assume you are following these setup instructions ? https://support.apple.com/en-gb/HT201729

[Anonymous]

Thanks for all your suggestions people, yes, we have followed those set up instructions each time we have reset the iPhones to see if the exchange e-mail works but unfortunately no joy.

[adamtemp64]

@Anonymous I would sugget your it guys talk to Microsoft re exchange issues as when I was on a Microsoft 365 business account and using exchange servers we had no issues . It could point to a server side issue re security access over the mobile data network .