Ray said:
Hi, I'm not able to receive any emails from a customer whose emails has blank
entry in the From field. Is there anyway to tweak Outlook so that I can
receive these type of emails? btw, I'm using outlook 2003.
E-mail is not delivered directly based on the To, Cc, and Bcc headers
(because these are *data* within the sender's message). The e-mail
client aggregates the contents of these fields to compile a list of
recipients to send a RCPT-TO command to their mail server when the
sender submits their message to their mail server. A separate RCPT-TO
command is sent for each recipient and that is followed with the DATA
command that contains a single copy of the sender's message (and which
includes the "headers" within the message).
Similarly, the From "header" is nothing more than data within the
message from the sender. It is one of the return-path headers. Outlook
doesn't require that the From header exist to *receive* an e-mail (and
it may not be used when replying to it). The From "header" is just data
within the sender's e-mail and can be whatever the sender wants (within
any restrictions imposed by their e-mail client or their e-mail
provider). It doesn't have to be their e-mail address. It doesn't even
have to be an e-mail address. It can contain any string (and that
includes a null string). If the From header exists in the received
e-mail, that you don't see the e-mail because it has a null value is
something defined in a rule that you created or in your anti-spam
software.
However, RFC 2822 for Internet Message Format, section 3.6, requires
that there be one and only one instance of the From header (and not as
to what it contains for a value). If the From header is entirely absent
then the sender is non-compliant with the RFC regulating the structure
for e-mails.
You said that the From header was blank. That is not the same as saying
the From header is absent. If the From header is absent, tell the
sender that they are sending non-compliant e-mails and they must include
the From header. If the From header exists but is blank, they are
compliant. There also is no reason that Outlook would not receive
e-mails with a blank (null) valued From header. Something else you
configured within Outlook or something external, like your anti-spam
software or your e-mail provider, is blocking the reception of those
e-mails although they are still RFC compliant.
If you can use the webmail interface to your account and see that the
inbound e-mail is residing in your mailbox then Outlook should receive
it regardless of the value of the From header. That header is not used
when your e-mail client sends a RETR command to retrieve that message.
Your e-mail client sends a LIST and/or UIDL command to get a list of
messages in your mailbox up on the mail server. Based on its history of
past UIDs, it decides which ones are new in your mailbox. For each new
item, it sends a RETR command. There are no filter commands that say
"Do a RETR command but only if the From header (which requires reading
into the message before retrieving it) has a null value". RETR just
does a retrieve of the entire message.
If the sender's message isn't showing up in your mailbox, you'll have to
speak with your e-mail provider as to why they block messages that have
null-valued From headers. When they receive a message (the sending mail
host sends a RCPT-TO command to the receiving mail host), the receiving
mail host doesn't go interrogating the "headers" which are inside the
message. That interrogation is done afterward by their anti-spam or
anti-virus software which then opens the message to scan it. If it made
it into your mailbox (as seen by looking in the Inbox folder when using
using the webmail interface to your account) then Outlook will retrieve
it. Outlook is just going to send a RETR command to retrieve the
message and cannot interrogate that message until *after* it has
actually retrieved that message.
Some e-mail clients can issue the "TOP 0" command (retrieve all headers
within a message but zero lines of the body) to retrieve just the
headers and exercise their rules against those messages based solely on
the headers. Outlook Express can do that and why it has the "delete
from server" clause to add to a rule. But then YOU are exercising a
rule that you defined to delete that message if, for example, your rule
tests for a blank value for the From header (I test that there is no "@"
character in the From header). However, Outlook doesn't support the TOP
command and only issues the RETR command. That means Outlook gets the
entire message, and only after getting the entire message does Outlook
then exercise its rules against it.
It is not that Outlook refuses to do a RETR to get a message that may
happen to have a null-valued From header within the message. You have
configured Outlook to do something with that message *after* Outlook has
retrieved it. You have a rule that checks the From header. You added
that sender to your Blocked Senders list. You configured your anti-spam
software to block (delete) messages with a blank From header.
