How I Fixed an iPhone that Couldn’t Get Mail Unless On WiFi

iOS 10 Mail icon

— How I Fixed an iPhone that Couldn’t Get Mail Unless On WiFi —

I had an interesting problem last month. My friend Laura dropped her iPhone 6 and cracked the screen. She was going to get a new one, but decided to get the screen replaced and keep using it. Everything seemed fine after the repair.

But Then…

Laura called me to say that her email wasn’t working on her iPhone. She kept getting messages like this one:

iOS Cannot Send Mail message
Cannot Send Mail

I had her check the settings for Mail and they seemed fine. I tried setting up one of my spare iPhones with Laura’s email settings and I was able to send and receive from both of her accounts– obviously, if I could sign into her accounts, we knew the right settings. And since I was able to send and receive emails from both of her accounts, her email accounts were working fine.

I asked Laura to try sending me an email and to our surprise, it worked. She also received my reply. Problem over, or so we thought.

The next day, I got another call from Laura. “It’s not working,” she said. This time, I asked her where she was. “Florida,” she said (I was in California so I couldn’t fix her iPhone in person). She was on her way to a meeting. In the car. The funny things was, we both knew Mail worked perfectly yesterday.

I asked Laura, “Where were you yesterday, when your iPhone’s Mail worked?”

“In my hotel,” she said. “On their WiFi.” “Aha,” I thought. “Mail works over WiFi, but not on Verizon’s network. Something must be wrong with Cellular Data.” Maybe it was turned off. Laura checked (Settings/Cellular)– it was on.

Cellular Data in iOS-- ON
Cellular Data in iOS– ON

My next guess was that maybe there was something wrong with Laura’s account with Verizon. Maybe she was over her data limit. Laura checked into it– no problem.

Then I had a flash of inspiration. “Try going to web pages with Safari,” I said. My guess was that this would not work and that we would narrow our problem down to something wrong with the network connection (or maybe the antenna) when not on WiFi. But guess what? Safari worked just fine over cellular, in the car.

To recap: when on WiFi, Safari worked, and so did Mail. When on cellular, Safari worked, but Mail did not. We knew we had the right settings for Mail because the accounts worked fine when on WiFi. And we knew the cellular data antenna worked, because we could use Safari and load web pages when not on WiFi.

Laura went to a nearby Apple Store, told them her story, and they sold her a nice new iPhone 7, hoping it would solve her problem. She left the iPhone 7 in the box for me to set up upon her return to Los Angeles.

At this point, the old iPhone still didn’t work right. Actually, the only thing it had trouble with was Mail– the iPhone would not send nor receive email unless the iPhone was on WiFi. Everything else worked fine– Messages, phone calls, Weather, other apps.

The old iPhone was backed up to iCloud, so I set up the new one by restoring that backup to it. Restoring a backup to a new iPhone can be a very lengthy process, as this one was, but I had to wait it out to see if the new phone could get mail when not on WiFi. When the new iPhone was ready I tested sending and receiving email over WiFi, and it worked perfectly (as expected). Then I turned WiFi off and tried doing it over cellular– and it did NOT work.

Now I knew we had a software (or settings) problem, because the new iPhone (a clone of the old one, software-wise) had the exact symptom exhibited by the old iPhone. In effect I’d copied the problem to the new iPhone.

I looked at Cellular again. Yes, it was on. But this time, I scrolled down. This revealed a section of Cellular’s settings that I hadn’t looked at. It’s called “Use Cellular Data For:” and here’s how it looked.

iOS 10 Use Cellular Data For
iOS 10 Use Cellular Data For

Scrolling down a little more I saw this:

Cellular Data was OFF for Mail!
Cellular Data was OFF for Mail!

I was very, very surprised to find that “Use Cellular Data For” was turned OFF for Mail! So many apps were allowed, but not Mail. Naturally I flipped the switch for Mail to “On” and the problem went away.

Note: if, for some reason, you turn “Use Cellular Data For” to OFF for Mail, you’ll get a big warning telling you your mail won’t work right if you do that. Apparently, with Laura’s iPhone, the warning was not seen, or not understood– certainly not remembered.

As usual, solving this problem started with figuring out what the problem was. We started out thinking the problem involved the iPhone settings for Laura’s email accounts, but that wasn’t it. Then we thought cellular data might be off– but we saw it was on. Then we thought it might be something wrong with the cellular antenna, but we were able to use Safari over cellular, so that wasn’t it either. Then we thought there might be something wrong with Laura’s account with the cellular carrier– but that wasn’t it (Verizon said so, and again we knew we could use Safari, and that uses the same cellular data as the Mail).

Finally, having looked at the master switch for Cellular data a second time, we had the idea of scrolling down (on a Settings page that doesn’t look as if it has anything to scroll). I think it was just bad luck that the Cellular settings screen fit so perfectly on the iPhone 7– had it been cut off in the middle or something, we probably would have realized that there were more settings below and that we should scroll down to see them. Anyhow, once we saw the “Use Cellular Data For:” section, we zeroed in on the problem, and fixed it right away.

Sliding the switch to let Mail use cellular data was easy. The hard part was figuring out what the problem actually was. Sometimes it’s the other way around– easy problem to figure out, hard problem to correct. Here’s a story about a wrestling match I had with an iMac a few weeks ago (I won).


45 thoughts on “How I Fixed an iPhone that Couldn’t Get Mail Unless On WiFi

  1. I don’t know if you will ever see this, but THANK YOU! For almost a month, I’ve had the same problem. Tried everything. Was using the GMAIL app and just honestly don’t care for it. This solved my problem. Thank you!!

  2. Thank you Christian. It turned out i didn’t have Mail turned off to use cellular data but I had ‘Watch’ turned off. Turned watch back on and voila fixed!! I have been pulling my hair out for days over this. Thanks again

  3. Thank you so much. Had same problem for 6 weeks. Like most complicated problems the solution is way simpler that what we were looking for.

  4. I have asked tech guys who do this for a living and my months-long problem just went away with a simple google search. Thank you!!!

  5. Christian,
    Thank you so much for such a great post, along with the pictures of the screen. It was very helpful and you have provided a wonderful service for many. Easy fix, if you know where to look.

  6. Another desperate user saved! Thanks so much for your skills, clear step-by-step explanation and generosity in sharing with the rest of the world.

  7. Christian!

    YOU MADE MY WEEK!!!!!!!!!!!

    I have been looking for this for months! I was going crazy!
    Thank you so so so much.


  8. Thank you! I had the same problem today, googled “my phone can get email on wifi but not with cellular data” and your article came up!

  9. Thank you!!!! This fix was exactly what I was looking for, and it was driving me nuts. Buried down in the UI, never even thought to scroll down once…

    1. I had exactly the same experience– I never thought to scroll down because what I saw of “Cellular” settings fit perfectly on my iPhone’s screen– and of course there are no scroll bars on the iPhone to indicate that there’s something to scroll! Glad I could help you.

  10. You are brilliant! our dept IT person couldn’t fix the problem. Why didn’t I think to google the problem sooner. Gah! THANK YOU!!

  11. Thank you for doing all the hard work for us! I am part of the growing populace that troubleshoot with the “Google/Youtube first, use brain second” mantra. Nice to see folks out there still doing it the old fashioned way! Thanks a million. Fixed my co-workers phone in just a couple of clicks. Now he thinks I am a sorcerer or something.

  12. Thank you thank you thank you! I went to the Apple store, but they couldn’t help!!!, but reading this solved this old problem i 5 minuts (I should have googled before !)
    Greetings Frank

  13. Hi! I work tech care and had a customer with this same issue, and it resolved it perfectly, thank you!

  14. Add me to the list. I’ve had this problem since getting my phone in Dec. I feel a bit stupid for not going to the store sooner but i just dealt with it. Thank you!

  15. Add me to the list. I’ve had this problem since getting my phone in Dec. I feel a bit stupid for not going to the store sooner but i just dealt with it. Thank you!

  16. My problem is that mail, Gmail, Hangouts doesn’t even show up in the list as an option to turn off or on cellular data used for.

  17. Same problem, similar solution. I checked my settings, and Mail was on. Turned it off and on again. Sorted

  18. Thanks for the help, didn’t know what to do….

    The most surprising part of the story is when your friend Laura goes to the Apple Store and instead of telling her how to solve the problem, the sell her a brand new iPhone 7…. seriously?

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