Why can I not block this sender?

[lrex]

I received two suspicious emails from apache@andromeda

These had pictures that were prevented from downloading and when I
downloaded them the message was totally blank. The sender's email address
had no domain name! So, when I tried to add the sender to the Blocked
Senders List, I recevied the message:

"The e-mail address or domain name you entered is not valid."

How can someone send me an email without having a domain name suffix on
their email address? and Why can't I block it?

 

[MichaelHensley]

How can someone send me an email without having a domain name suffix on
their email address? and Why can't I block it?

The SMTP protocol doesn't require a valid (or even ANY) "From:" address.

Blocking email based on the "From:" field is generally a waste of time
anyway, since most spammers used forged (and constantly changing) "From:"
fields.

 

[Brian Tillman]

I received two suspicious emails from apache@andromeda

These had pictures that were prevented from downloading and when I
downloaded them the message was totally blank. The sender's email
address had no domain name! So, when I tried to add the sender to
the Blocked Senders List, I recevied the message:

"The e-mail address or domain name you entered is not valid."

How can someone send me an email without having a domain name suffix
on their email address? and Why can't I block it?

Examine the headers and see if there's a value there you can use and then
use a rule with the "with specific words in the mail header" condition. You
could also use the "with specific wordds in the sender's address" condition
and make "andromeda" the specific word.