I'm the IT professional of a certain office. one specific person in the office cannot send email to one specific person outside the office.
We'll call this person address A.
and the person they cannot send email to, address B.
Address A cannot send email to address B.
Address B CAN send email to address A.
both companies are using outlook to check email
both compaines have an exchange server set up, but do not revieve their pop3 email through the echange server.
both companies are using the same shared hosting company. both offices can send email to anyone else in either office.
I set up address A's email address on a test computer outside the office, and was able to send email to subject B.
I'm baffled. There are no rules, no junk email filtering, nothing.
I also tried to set up address A to recieve pop3 email through the exchange server, and the same issue happened. Address B can send to Address A, but Address A cannot send to Address B, even when replying.