Cant send mail after new email address

 Friend changed email address. I have made the change and now I can not send him any emails. I keep getting the message , Cannot send message. (mail recipient not accepted by the server). How can i fix this please. I am using eM Client 6.0.21040.0. I have no problems with any other mail. Regards Chas C

Hi Chas, can you please install this update and check if the issue persists, http://www.emclient.com/dist/v6.0.21151/setup.msi ?
What mail service are you using with eM client? Can you please make a screenshot of the error you’re seeing, and when it occurs, please switch to the “Log” tab, copy the content of the log and post it here on the forum.

Thank you,
Paul.