A FQDN is a fully qualified domain name which can be

domain.com
www.domain.com
mail.domain.com
pie.domain.com
anything.domain.com

Basically whatever you like as long as you own domain.com

All you need to do is be consistent /etc/hostname /etc/hosts /etc/mailname and myhostname all need to be the same one.

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How to ask for help
1. Give details of your problem
2. Post any errors
3. Post relevant logs.
4. Don't hide details i.e. your domain, it just makes things harder
5. Be polite or you'll be eaten by a grue

Thanks obs!
How much i´ve learned today.
The documentation in the library is not that "consistent"


One more thing.
Do i need to set a reverse DNS anyway?
What is that for?

Thanks

The library is pretty good but it can be confusing it's like information overload.

Anyway yes set rDNS, reverse dns resolves your ip address to your domain, mail servers use it to help prevent spam.

_________________
Paid support
How to ask for help
1. Give details of your problem
2. Post any errors
3. Post relevant logs.
4. Don't hide details i.e. your domain, it just makes things harder
5. Be polite or you'll be eaten by a grue

Thank you very much for your help!

In my site´s script, socialengine, i can now send emai to all members in the administration section, but on the public side of the site, there is an invite page that members can inite anyone to join, but it´s not working there.
I just did the basic configuration of postfix, didn´t setup any Email Virtual Hosting in "/etc/postfix/virtual", i think this is to setup accounts to receive emails, am i right?
Do you have any clues of what can be wrong or missing?

What does tail /var/log/mail.log say after you try and send an email from the invite page, you don't need to set up any virtual hosting unless you want to receive emails (which you don't).

_________________
Paid support
How to ask for help
1. Give details of your problem
2. Post any errors
3. Post relevant logs.
4. Don't hide details i.e. your domain, it just makes things harder
5. Be polite or you'll be eaten by a grue

Strange, i tried another email receipt and it was sent.
The gmail is not received, i tried again, but the hotmail was.

I tried to send to 3 emails: gmail, hotmail and centroin, the log shows only the hotmail and centroin, it ignores the gmail....

Your log shows one to gmail here

Feb 25 15:55:38 loseweightforever postfix/smtp[2339]: 2B579105CC: to=<domainhut@gmail.com>, relay=gmail-smtp-in.l.google.com[209.85.225.27]:25, delay=0.59, delays=0.05/0.01/0.16/0.37, dsn=2.0.0, status=sent (250 2.0.0 OK 1298649338 ut8si1846805icb.77) 

Try setting up a spf record (see here http://old.openspf.org/wizard.html) then give it a day and see if you still have problems.

_________________
Paid support
How to ask for help
1. Give details of your problem
2. Post any errors
3. Post relevant logs.
4. Don't hide details i.e. your domain, it just makes things harder
5. Be polite or you'll be eaten by a grue

That to gmail was an old one, from the admin area, that works...

Ok, i will give that a try.
But i have a question, just noticed, when i sent the email to Centroin, when i checked the inbox, in the Sender field appears : SocialBits@loseweightforever.biz

In hotmail or Gmail appears only SocialBits. My FQDN is loseweightforever.biz, but socialbits is another site, another subject, so it feels strange. Do you know how to managed that?

Thanks a lot.

Your script needs to set the correct headers and use the php mail additional parameters to add "-r fromemail@domain.com" (replacing fromemail@domain.com with the real email).

_________________
Paid support
How to ask for help
1. Give details of your problem
2. Post any errors
3. Post relevant logs.
4. Don't hide details i.e. your domain, it just makes things harder
5. Be polite or you'll be eaten by a grue

Thanks obs!
Really helpful.