Attachment Problem with one email address but not with others

I am bemused. I have a new Bold 9900. I have set up 3 email accounts on it. All different providers. On two of the accounts I can receive attachments and open them fine: documents; pictures; etc.

On the third account, which is actually my main one, attachments will not open. When I try to open or download the attachment, I get the message "This attachment type cannot be viewed on your device". This problem email account has an address @btinternet.com which is part of BT Yahoo, a main UK provider.

Any advice would be gratefully received. Thank you.

You should contact that email provider and see if there some type of block is on your email account.

Sent from my BlackBerry 9930 using Tapatalk

I asked a question before and have given more useful information below to help identify the problem.

I have a new Bold 9900. I have set up 3 email accounts on it. All different providers. On two of the accounts (�good accounts�), I can receive attachments and open them fine: documents; pictures; etc.

On the third account, which is actually my main one, attachments will not open. When I try to open or download the attachment, I get the message "This attachment type cannot be viewed on your device". This problem email account has an address at btinternet dot com which is part of BT Yahoo, a main UK provider.

The additional information is:
1) This same btinternet account worked absolutely perfectly with my Blackberry Curve from which I changed last week.
2) If I receive an email with an attachment into the btinternet account on the Bold it cannot be opened. If I then forward that email from within the Bold to one of my �good� accounts, a strange thing occurs. The attachment cannot be opened within the Bold on the good account; but that forwarded email is also of course received in Outlook on my laptop and the attachment appears there to be absolutely normal and opens ok.

Many thanks for any help which you can offer.