how to get rid of an outlook.com address which invades my btinternet resulting in unanswered pos

[HelenS]

More than one, intermittently.

[licquorice]

This is very odd, I can't see how the mails could have originated from you with an outlook.com address. Are you sure they are the genuine emails you sent and didn't get a reply to rather than spurious mails.

Are you sending to more than one recipient and perhaps one of the recipients is also forwarding your mail using an outlook.com email address. Your mail may not have arrived and they are replying to the forwarded mail thinking they are replying to you. If that all makes sense.

Is the part of the address before the @ outlook.com the same as the part before your @btinternet.com address?

[HelenS]

Yes as far as I know

[HelenS]

I have just emailed a contact who has verified that if she replies directly it goes to outlook.

[licquorice]

Can you ask her to see what address it comes from without attempting to reply. With some mail systems it is possible to set a 'reply-to' address different to the sending address but that isn't possible with BT webmail.

[HelenS]

I have just sent an email, using the newly downloaded app. She deleted my outlook address from her contact.  As she was about to reply, up came the outlook address first, again. Aarrggh!

[licquorice]

It sounds as though the problem is at her end.

Not sure how a contact list is involved if she is just replying.

[HelenS]

 I realise I haven’t followed through with your previous answer but I feel bad about asking her to help sort this out at this time of the year!

[HelenS]

The difficulty has arisen with several of my contacts but I shall email them all to ask them to remove any reference to an outlook address for me. Thank you for you time.

[Carlusha]

Meanwhile, have you tried sending an email to yourself and any other email addresses YOU may have?