cannot send outgoing mail

[Contained]

i can't send outgoing mail on my Outlook 2003.

after attempting to do so, i receive an undeliverable
message with the error message " 551 Command RCPT User not
local and relaying not permitted from you".

the same thing happens when i attempt to send again.

i have zonealarm running. have set zonealarm to allow
outlook 2003 both internet access and to act as server.

also have NAV 2002 running. email protection is on. but
even when i turn email protection off, the same thing
happens. same occurence when i disable NAV 2002.

it seems to be v inconsistent. managed to mail outgoing
before after disabling either zonealarm or NAV, but when i
repeat it, it doesnt work. what's wrong?!

 

[Patrick Reed [MVP - Outlook]]

Have you checked with your ISP? Their SMTP server is the one rejecting your
message. More than likely, they require authentication for submitting SMTP
message to their server. You can try setting Outlook to use the same
credentials for outgoing messages as you use for incoming messages by
checking that option from Tools | E-Mail Accounts | View or change existing
e-mail accounts | Next | <select account> | Change | More Settings \
Outgoing Server.