Problem sending E-mail through my ISP smtp-server.

Hi.

I have recently moved and I had to change my internet provider. Now I've discovered some problems.

I had no problems whatsoever before when people wanted to register on my gallery site. But now, after registering on my site no confirmation e-mails reaches the end user and me as an administrator.

The message I get when I run the e-mail test on the diagnostics page is this:

"Error: Sending mail via the smtp method failed with these errors: Array ( [0] => Command rejected no valid MAIL FROM: command received yet [1] => No sender. ) Error: Sending mail via the smtp method failed with these errors: Array ( [0] => Command rejected no valid MAIL FROM: command received yet [1] => No sender. )"

I'm sure that my smtp settings are correct since I have the same settings in my thunderbird mail client which works prefectly fine.

smtp server: smtp.ISP.net
sender hostname: localhost
port: 25
user: myuser
pwd: mypwd

I have changed the settings in php.ini to correlate to the new ISP:

[mail function]
; For Win32 only.
;SMTP = localhost
SMTP = smtp.ISP.net
smtp_port = 25

; For Win32 only.
;sendmail_from =

My ISP blocks port 25 so its not possible to have your own mail server without relaying the traffic through smtp.ISP.net.

I changed the configuration to use the internal PHP mail() function instead. That worked when I used the diagnostics test. It also worked when I retreived a lost password for my user. But it did not work when I tried to register a new user.

What could be the problem?

Regards Mats

The following information is required to get an answer:
Get this information from the PHP diagnostic (in the configuration wizard).
Gallery URL (optional but very useful): www.euren.se:5050
Gallery version: 1.5.6
Apache version: 2.0.55
PHP version (don't just say PHP 4, please): 5.1.2
Graphics Toolkit: NetPBM and Image Magic
Operating system: Windows XP SP2
Web browser/version (if applicable): Firefox 2.0.0.4 and IE 6.0