Identifying e-mail rejection issues: Sender denied
In order to understand why an e-mail message is rejected, one simply needs to delve into the bounce message. Many users find e-mail error messages confusing or intimidating. With practice, anyone can competently figure out the meaning of an error.
Figure 1: Sample e-mail bounce message
In this example, Gmail user Goomail Student could not reach the campus address Campus.User@csulb.edu, because the recipient's e-mail system blocked the sender. The error inside the red box "Sender denied" indicates explicit blocking by message recipient.
The campus recipient Campus User needs to remove the sender's e-mail address or domain by updating his/her Blocked Senders list.
Open Blocked Senders List
With Outlook open and the Home tab on the Ribbon active, click on the Junk button (in the Delete group) and select Junk E-mail Options. Once the Junk E-mail Options window appears switch to the Blocked Senders tab.
Figure 2: Junk Email drop down menu
Remove a Blocked Sender
Find the sender's e-mail address or domain in the Blocked Senders list and click Remove to delete it, then click OK.
Figure 3: Blocked Senders dialog box
Once you have updated the Blocked Senders list, tell the message originator to send their message again.