Nokia 9210 Email problem: Invalid Address in To Cc or Bcc

This happened to me when the SMTP server was refusing my "return" address, i.e. when it was needed that the return address was from the same domain of the smtp server. Please check that your provider does not need a particular combination of smtp server and email data.

If you need SMTP authentication to send email you'll get this. I don't think there's any way around it unfortunately except try a different ISP...

Eventually I found a workaround for this nuisance. It works with my telco smtp server, but it is not guaranteed with other's :roll:
In the "servers" section of email configuration, I've set a string as such:

myrealusername@myrealdomain , mytelcousername@mytelcodomain

i.e. first my preferred reply-to address, then comma, then the address on telco domain which works as reply-to field.

The smtp server gets persuaded that I am a loyal user by reading the latter, but the email address which shows on my sent messages is the former.

Don't pass this to my telco! Those stupid marketing assholes first tried to impose the use of a proxy server to monitor the places where people intended to navigate (preventing the use of telnet, ftp and the so), then now started this authentication thing which does not really prevent anybody to send mass email, and forces people to use *their* email server (which of course is very often off for maintenance).