Charles Marcus wrote: > On 10/6/2008 2:29 PM, mouss wrote: > >>> Does simply adding the additional domain example2.com in >>> virtual_mailbox_domains allow me to use the additional hostname >>> smtp.example2.com (in client configurations) for sending mail, >>> assuming example2.com is listed in virtual_mailbox_domains and have >>> appropriate DNS & MX records for the additional domain(s) pointed >>> to the appropriate IP? >>> > > >> receiving mail has nothing to do with sending mail. >> > > I know... thats why I was asking about how virtual hosting works with > respect to SENDING mail via CLIENTS (MUAs). > > I'm going to be writing up instructions for users who will be using > these new domains how to set up their mail clients (Thunderbird mainly, > but I also include instructions for the Microsoft clients)... so I > wanted to confirm that I can use the hosts 'smtp.example1.com' and > 'smtp.example2.com' for their SMTP (outbound) server setting in their > clients. > >
This depends if you permit_mynetworks and permit_sasl_authenticated before any reject actions. I could put [EMAIL PROTECTED] even if I only control example.com as the envelope sender in my MUA. Provided I'm within the permits, Postfix will not care. >> when you send mail, the hostname is used as the HELO (EHLO) argument. >> > > I'm not talking about HELO commands issued between MTAs... I'm talking > about hostnames used by MUAs for SENDING mail... > MUAs typically use the hostname they are given. A good majority of Win clients, for example, use a single name as it's helo and not fqdn. Do you care? Only if you configure Postfix to reject_non_fqdn_hostname somewhere. > >> This identifies the _server_ that sends mail. It has nothing to do with >> the domains you host. >> > > Well... it does, if I want users getting mail at example1.com to be able > to reference smtp.example1.com in their client settings. > > It will be awkward to tell a user to put smtp.fred.com for their > outbound server setting, if their email address is [EMAIL PROTECTED], don't > you think? > > Think hosted domain. Server can only have one name, but serves several. MXs that check only care if the sending domain matches in DNS as being responsible, preferably an A or MX record. Will bogus mails get rejected at the source? Maybe, though some postmasters care not, some actually do check. Brian
