Hi there Steven and welcome
Can you tell me please which email program you are using? (both type and version)
ok, so when sending from this app on you iPhone you get this issue correct?
If so, on the iPhone hold the home and power buttons for about 10 seconds until you see the apple logo then release.
Let then phone restart and tell me if it now sends correctly
You are sending via the actual app correct? Not via the email app on the iPhone?
ok, I want you to reinstall the app please.
On the phone, hold your finger on the app until it wiggles and then press on the X to uninstall it.
Then restart the iPhone like we initially did, install the app and tell me if it then sends correctly please.
ok, but this is why I am asking about the problem being within the App, so your now saying it is any email you send on the iPhone, NOT just via the app?
ok... then go to settings, Mail, and press on your email account and press Delete Account
Once done, restart the phone, add the email account again and tell me please if it now sends correctly.
Go to Settings >> Mail, Contacts, Calendars, there is a setting called “Always Bcc Myself”
Turn this off and send an email
Let me know the results please
Can you go to settings, general, reset, reset settings
Once done, restart the phone and tell me how it now sends please.
ok, then you will need to do a full reset of the phone, and reinstall it.
First, backup any data you need to keep from the phone eg: Photos, Videos ect.
Apps you will need to reinstall
Then go to settings, general, reset, erase all content and reset settings.
Once done, setup the phone, add the email account again and tell me how it now functions please.