SeaMonkey RECEIVES but can't connect to server to SEND email

[rogerpb]

Excuse me if I am posting to the wrong place, but I queried why I could not send messages in seamonkey, and got in return ten pages ( not all relating to seamonkey, and most many years old.) Which are the newest ones, on page one or page ten, and how can I restrict the harvest to the most up-to-date queries and replies?

My question specifically is that after having problems with Outlook 7 receiving mail, though it could send, I tried installing Seamonkey. I checked the account settings with my service provider, UPC. Seamonkey downloaded all incoming mails. However, when I attempted to send mails, I got the following message:

The message could not be sent because connecting to SMTP server mgate.chello.at failed. The server may be unavailable or is refusing SMTP connections. Please verify that your SMTP server settings are correct and try again, or contact the server administrator.

Next, I installed Seamonkey with the same settings on my Samsung Ebook, which uses Windows XP with all service packs. It functioned perfectly, receiving and sending mails with no trouble.

UPC could not help, was not familiar with Seamonkey so asked me to instal Thunderbird and/or Windows Live Mail.
I tried both. Thunderbird took over the settings it found for Seamonkey. It displayed the incoming mails. But when I tried to send I got:

An error occurred while sending mail. The mail server responded: 5.1.0 Authentication required to send email as <translator@chello.at> on submission port. Please verify that your email address is correct in your Mail preferences and try again.

UPC had no idea what was meant by “5.1.0 authentification”.

I next tried Windows Live Mail. Again, this could receive mail, but not send it. I got an error message:
Subject 'another test'
Server: 'mgate.chello.at'
Windows Live Mail Error ID: 0x800CCC0D
Protocol: SMTP
Port: 25
Secure(SSL): No
Socket Error: 11004

It seems UPC, my provider, is totally unable to help, and the fact that Seamonkey works on my ebook suggests that the programs are not at fault. But what could be the cause of this extraordinary problem on my Desktop PC, where Outlook can send, whilst neither Seamonkey nor Thunderbird can (not to mention Live Mail) ?

The only difference in configuration is that the desktop (Win 7 Ultimate, SP 1) has AVG installed. However, this does not prevent Outlook sending emails, and even when I turned the check of outgoing emails off, I was still unable to send any from Seamonkey (latest edition) on my laptop, and the sent mail folder remains empty. My ebook has XP SP3, the same account settings, can send and receive and has a folder of sent emails. The Desktop uses LAN and the ebook WLan, using the same router.

[therube]

SMTP authentication

UPC: Thunderbird

[tuebor1828]

I don't know if you have managed to correct the error in sending of email, in Seamonkey or Thunderbird, while using att.net. I changed my outgoing SMTP to the following: smtp.mail.yahoo.com. It works just fine for the time being.

[dadob]

Here's how I solved smtp connection in my Seamonkey email

in seamonkey's browser type about:config

type in the about:config search box smtp

look for mail.smtp.qos a few lines down mine was 1 I changed it to 0
next two lines one ending in domain server the next ending in host name server
were both true I made them both false. It had no effect but my other seamonkey was set that way. Probably not important but the qos setting is!!!!
finally Close the about:config window to save settings
and try sending email........ This is assuming you have send email set up
properly in mail account settings in the bottom category labelled outgoing smtp
server.

I have my gmail imap recieve account defaulted to smtp.gmail.com for server name
then 587 for smtp or you can try 465 for imap.gmail.com or for pop 25
smtp.gmail.com. I have starttls = normal password and my ==username of the
default send account in the remaining spaces.

I have heard people say username@gmail.com is sometimes helpful.
Of course put in appropriate proper settings if you have another email service
not gmail
The critical about:config setting in smtp search list was smtp.gmail.qos set to 0
now it's working on this computer after 2 years of no smtp
service. Probably works in other email iterations from Mozilla. Blessings.