I have had several instances recently where emails sent from my me.com address using Mail are reported as not received by the recipient. This does not always seem to simply be an issue of it going into their spam box. Are there any settings that I should check my end to avoid this problem?
Thanks for your comments and sorry for delay in replying as have been away. They do not bounce back to me. I thought it might just be affecting emails to new recipients but I cannot prove this. At least there does not appear to be anything more I can do, although I have started a gmail account which may be more reliable.
Do you mean then that the recipient says "I didn't receive your email"? If so, get them to look in their spam folder both on their machine and at their email provider using the webmail service.