problems sending email

[Guest ewel]

Hi,

I have a strange issue with email from my phone. If I want to send a message, I sometimes (but not always) get a message in the inbox from System Administrator with subject "Invalid message recipients" which says: "Your message '[subject]' was not sent and moved to the Drafts folder. The following reciepients are invalid: [email address]."

I have had this with some email addresses but not with others. For example, addresses ending with '.info' or '.name' had an issue, as well as '.co.uk', but '.com' has not given problems so far.

Could it be that the email software does not recognise all top level domain name extensions?

Thanks for any help you can give!