PC e-mails?

Is your corespondent on AOL? Unless they changed their spam filters, your domain may be blacklisted. It appened to me several times. They where filtering on the sender's address and not on the content... If only one spam is received with a forged sender address from a given domain, then that domain could get blocked.

Ask your corespondent to check their Spam or Junk folders.

Try re-sending the message with a different subject line.

If there are any attachment, rename those with a different extention, like .txt and add renaming instructions in your message. Some e-mail systems are set to suppress messages containing some attachemnts to help "protect" their clients from malicious content.

Check if your message contain some sensitive words, like anything with a possible sexual slant. If that's the case, try rephrasing your text.

Electro
April 2014

With some systems you can request a Read Receipt. This can send you confirmation that the other user received the email. BUT it is a case of getting a receipt confirms the user received it, not getting a receipt does not mean the other user definitely did not get it. (They or their system can decline to send you a receipt.)

To help you more simply, ask the other user to check their spam filtering in case you are being filtered from their inbox. Their Internet Service Provider might be filtering spam as well as their own email software.

Neil D
April 2014