Duplicate email sending to the same contact

[RosieC20]

My Dad has noticed today that his emails are duplicating and sending to the same person maybe up to 6 times. Any help on what is causing that would be great. 

[gg30340]

Does this only happen with the one recipient?

Are you sure the problem is at your father's end and not with the recipient.

How does he access his email, is it using an email client/app or by using webmail (using a browser)?

Do the multiple emails show up in his sent folder?

Depending on how the recipient access his/her email it may be that the problem is at their end. If the recipient is using an email client/app it could be that once it has arrived at the recipients email account it is not being marked as downloaded and is being repeatedly downloaded and this would make it appear that the email has been sent multiple times.

Can you check with the recipient how they are accessing their email account and can they check their list of emails on webmail (using an web browser) to see if the muliple email from your father has been sent at the same time 

[RosieC20]

He uses the BT mail app. I’ll check on the other queries but when he sends an email to himself as a test. His email is in the From section and he can see his email address repeated 5/6 times in the To section, even when he has only sent the email once. 

[gg30340]

I would not use the BTMail app as there are far better free email apps available. He could try the Bluemail app. 

Can you get him to send an email to yourself using the following link in a browser

BTMail 

rather than the BTMail app to see if there are multiple emails being sent and received.

When he sent the email to himself, did he receive 5/6 emails?