liya wrote:

I am receiving these emails but I am troubleshooting for my colleague
and all the measures I have carried out to eradicate this problem
seems to be of no avail.

What version of Windows does your PC run? What type of account is the
sender using? If the sender opens your contact record, double-clicks your
email address, does the sender see an "E-mail Properties" dialogue? If so,
what does the "Internet format" drop-down at the bottom indicate?
--
Brian Tillman [MVP-Outlook]