This shows you the differences between two versions of the page.
Previous revision | |||
— | reference:smtp_direct [2018/11/14 10:45] (current) – external edit 127.0.0.1 | ||
---|---|---|---|
Line 1: | Line 1: | ||
+ | ======Mail Connectors -> Mail Senders -> SMTP Direct====== | ||
+ | VPOP3 can be configured to send mail directly to the recipient' | ||
+ | |||
+ | To have the most chance of SMTP Direct sending working you should have: | ||
+ | * A fixed IP address | ||
+ | * A reverse DNS entry set up for your mail server (contact your Internet connection provider to configure this) | ||
+ | * A business class Internet connection (home Internet connections are more often blocked by receiving mail servers) | ||
+ | |||
+ | [[mail_senders|Description of mail sending methods]] | ||
+ | |||
+ | =====Tabs===== | ||
+ | The //SMTP Direct// settings tell VPOP3 how to send mail directly to the recipients' | ||
+ | |||
+ | * [[Sender General|General]] | ||
+ | * [[Sender Direct Settings|Settings]] | ||
+ | * [[Sender Advanced Settings|Advanced Settings]] | ||
+ | |||
+ | =====How SMTP Direct sending works===== | ||
+ | For a full description of SMTP direct sending you should consult [[http:// | ||
+ | |||
+ | ====Finding target mail servers==== | ||
+ | When a mail server wants to send a message to a recipient, eg // | ||
+ | |||
+ | (If no MX records exist for the target domain, then the mail server does a DNS lookup for an A record for the target domain, and tries that). | ||
+ | |||
+ | For instance, the DNS lookup may return: | ||
+ | * mail.example.com | ||
+ | * mx2.example.com | ||
+ | |||
+ | In this case, the sending mail server will then resolve the **mail.example.com** name. This name may resolve to one or more IP addresses, so the sending mail server will try to connect to all the IP addresses of ' | ||
+ | |||
+ | Different sending mail servers try alternative servers in different ways. For instance, VPOP3 will currently only retry later mail servers if the earlier mail server doesn' | ||
+ | |||
+ | ====Error handling==== | ||
+ | SMTP has two types of error codes: | ||
+ | * Permanent errors - these error codes begin with a 5 (eg 520 or 507). If one of these error codes is received, then the sending mail server should not try to send the same message again | ||
+ | * Temporary errors - these error codes begin with a 4 (eg 415 or 421). If one of these error codes is received, the sending mail server should try sending the message again later (subject to retry limits). TCP/IP connection errors are treated as temporary errors as well. | ||
+ | |||
+ | If you send mail via an SMTP relay server, the relay server will usually accept the message immediately, |