OutLook Error smtp Cant Send Emails

[Me]

HI I got a problem on my laptop have recently setup outlook on my laptop and
find that when i am plugged in via modem to the internet I can send and
receive emails but when I plug it in my home network router I get the
following error message please can someone help me this only happens when
sending emails I am still receiving emails ok

An unknown error has occurred. Account: 'mail.XXX.com', Server:
'mail.XXX.com', Protocol: SMTP, Server Response: '554 Please check that your
outgoing
mail server settings are correct. contact technical support for
assistance.', Port: 25, Secure(SSL): No, Server Error: 554, Error Number:
0x800CCC6F

the mail setting are all correct because it works fine when I using a modem
but when it is plugged into my router it doesn't work I used to have a
freeserve account and that worked fine >>>????

 

[Guest]

The common problem that ocurs in this sistuation is that
your ISP's STMP server only accepts mail from IP addresses
within its network (ie you are connecting through that ISP)

When you are connected from your home network using a
different ISP, the SMTP server rejects your mail because
it does not know that you are not a spammer trying to
relay mail through it to disquise its origin (or other
more complicated reasons).

I do not recognize the error message exactly, but I bet
thats it.

Possible solution:
1) Enble the SMTP settings to authenticate. Then Outlook
logs onto the SMTP server to send mail, the same as it
logs onto the POP3 server to retreive mail. This is best
if your ISP supports it.

2) contact your ISP (the one that you use for you mail
account) and ask them how to use the SMTP server from
foriegn connections (IPs).

3) Change the SMPT server to that of your home, broadband
internet provider when you are connected to your home
network (leave the pop3 settings the same) and then change
it to the dailup ISP SMTP server when dialing in,

4) Use an ISP that uses POP before SMTP protocol (whenever
you collect mail (which is authenticated) it remebers the
workstation IP and allows it to use SMTP for a short while
afterward.