IOS 10.3.1 - iPHone 6S - I'm connected to my WiFi and STILL can't send attachment over 100MB

If it was working (and I do not see a limit on my own iPhone). turn the phone all the way off (hold down the top button and slide Power Off). Wait 2 minutes, power on and test.

Also make sure there were not any changes at the ISP that runs your email server.

Hi john:
I don't have an email server.
 I'm "sending" the >100mb file from my iPHone using the iphone email program sending it to my work email account.
I also tried a friends wifi account.   Same message.

Did you try resetting your phone as I suggested above?

Also go down the phone settings and reset the Network Components. This will mean remaking your Wi-Fi accounts so be aware of that.

What exactly is the Message you are getting?

Resetting your phone or network components or trying another WiFi network will not  resolve an issue if the SMTP server you are using has a restriction on file attachment size.  If the message indicates some file attachment limit then you must contact the person/department that manages your work email account.  They may have upgraded your work mailserver or modified settings.

Yes.  I did completely power down my iPhone and restart it.
the message I'm getting is:
Attachement is over 100MB
You must connect to a Wi-Fi network to send this attachment.

I am connected to a Wi-Fi network

ALSO, when an attachment is large.  My iPhone uploads it to some location and then I have 30 days to download it. So attachment size is not an issue.

That message has NOTHING to do with WiFi .. it’s a "feature" of the Mail app in iOS.  You'll get that message if you try and send large video files from the Photos app for example.

What I found is, that when you go to your photos and want to share video clip and attach it to an email this warning comes up, but if you go to write an email and insert same video clip there is no warning.
See a clip here on YouTube to illustrate
https://www.youtube.com/watch?v=f6eioPfSmDw

Basically you cannot attach files > 100Mb in Mail app in iOS without using a service like MailDrop .. details on the Apple Discussion forum
https://discussions.apple.com/thread/7492285?start=0&tstart=0

Okay.
I turned off the phone and turned it on.
I also reset all network settings.
STILL not working.

Maildrop is not working.
It used to work.  Is there a setting somewhere?

There is an older article here

https://discussions.apple.com/message/23128091#23128091

I think the issue must be external to your phone and where you download / send your email from / to.

Strange.
I just checked my HOTMAIL inbox.  When I send myself anything that's large, I get a message from my iPHone saying that Mail drop will be used.
I'm not getting that message anymore.

So based on that the issue is external to your phone. It does not appear to be the problem

ITS not allowed 25mb is the highest it will go --- the rules change because people would email software to others now if you want to move that large file you will have to use third party email and not google either so your best bet is dropbox or google drive

What mail account is setup in the Mail app on your phone?

Hi:
I'm using the iPhone's email app because when I try to send an attachment that is too large to be sent as an attachment, it prompts me to use maildrop.  However, i'm not even getting to that point!

I understood that from the entire trail. So you smaller attachments work the way that they are supposed to. What would happen if you either restart your phone or if you removed/readded the email account? (Feel free to chime if if you've already done these since moving up to 10.3.1)

I tried another movie -- 1.9 gig-- and I get prompted to place it in mail drop.
But this other movie the one I need to transfer and whose size I cannot determine-- does not get prompted to be placed into mail drop.
I did try restarting my phone but I did not try removing the email account.

You can't determine the size of the file you need to transfer? That might be the entire problem. Has your problem been solely with files from a specific source?

1. When I select a video or photo from my iPhone camera app, it does not display the size of the photo or video until after that object is attached to the email. It is at that point that I get prompted to use Mail drop or use a smaller sized graphic object.
2. I'm trying to send videos from my iPhone, nothing else.  I can send photos with no problem.

Alright. From what you are yelling us it seems to be only that one video. So would there be a way to get more information about it?

Exif Wizard
https://itunes.apple.com/us/app/exif-wizard/id387652357?mt=8

Install the app about to look into the file size of your video files.

For getting back mail drop, you need to do a soft reset of your phone by holding the on/off and volume-down buttons together for about 10 seconds until you see the Apple logo.

I installed Exif Wizard.  Holy cow.  What a great friggin app.  How come I'm only finding out about this now!!!

When I click on a video using EXIF, my phone "blinks" exits the app and takes me back to the home screen.
I never get to see the stats of the app.

If you are convinced your phone is the issue (and not a limit in the outside network), then back it up completely, do a factory reset and then restore your data. iTunes makes this fairly easy.

Seems like #a42106691 should be the solution.

Have you fixed the mail drop issue? A soft reset as mentioned in my comment should fix it.