Synchronet v3.19b-Win32 (install) has been released (Jan-2022).

You can donate to the Synchronet project using PayPal.

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revisionPrevious revision
Next revision		Previous revision
Next revisionBoth sides next revision
server:mail [2018/03/04 00:33] – [SendMail] Sendmail thread supports TLS now. deuceserver:mail [2018/10/29 15:13] – [Tags] Details on the FidoNet netmail gating and cleaned up the tags section digital man
Line 30: Line 30:
   cnnreport    sub:dove-deb   cnnreport    sub:dove-deb
      
-==== Tags ====+==== Special Addresses ==== 
 +Some specially formatted destination addresses (''RCPT TO'' addresses) are recognized and treated specially by the Synchronet SMTP server.
  
-Incoming email is scanned for To: headers in the format ''<name>#<tag>@host''+=== FidoNet === 
 +If the system supports [[network:FidoNet]]-style networking (has at least one address configured in [[util:SCFG]]->Networks->FidoNet->Addresses), then incoming FidoNet netmail messages are recognized with one of the following formats:
  
-Tag is extracted, and if it is not found in ''data/user/<usernum>.smtptags'' it is +  * ''//<name>//@f//<node>//.n//<net>//.z//<zone>//.fidonet'' 
-sent to the user.  If it DOES match a line in the smtptags file, the email +  * ''//<name>//@p//<point>//.f//<node>//.n//<net>//.z//<zone>//.fidonet''
-is rejected with a "no such user" error.+
  
-Using this this feature allows you (the sysop) to easily create "temporary" email addresses.  Once you +Example: ''rob.swindell@f705.n103.z1.fidonet''
-start recieving spam on one tag, just disable it.+
  
-===== SendMail =====+Note: the ''.fidonet'' host suffix is required even if the destination network is an //othernet// (not technically part of FidoNet proper). This is a "virtual" TLD, no DNS lookup is performed by the mailserver for destination hostnames with this suffix.
  
-The SendMail Thread is responsible for delivering mail using the SMTP or ESMTP protocols, optionally authenticating using PLAIN, LOGIN, or CRAM-MD5 SMTP-AUTH methods if required by an SMTP relay server.+=== Tags ===
  
-The SendMail Thread currently can service one outgoing SMTP/ESMTP session at a time.+The Synchronet Mail Server recognizes the incoming special address format: ''//<name>//#//<tag>//@//<host>//''
  
-===== Post Office =====+The //<tag>// is extracted from the address and if it is **not** found in the ''data/user/<usernum>.smtptags'' file, the mail message is 
 +sent to the destination user.  If the tag matches a line in the ''.smtptags'' file, the email is rejected by the mail server with a "no such user" error.
  
-The mail server also services authenticated "post office" requests from mail clients using the POP3 protocol, by default, on TCP port 110.+This feature allows you (the sysop) to easily create and use "temporary" email addresses without requiring additional user accounts.  Once you start receiving spam with a tag, just disable that tag by adding it to your ''.smtptags'' file.
  
-The POP3 server supports client authentication via the USER or APOP methods. +==== Anti-SPAM ====
- +
-The POP3 server can service multiple simultaneous incoming sessions. +
- +
-For IMAP support, see Deuce's [[service:imap|IMAP Service]]. +
- +
-===== Anti-SPAM =====+
 The Synchronet SMTP Server contains several anti-SPAM measures: The Synchronet SMTP Server contains several anti-SPAM measures:
   * DNS-based blacklist (DNSBL) look-up support with exemptions and multiple possible actions upon positive results   * DNS-based blacklist (DNSBL) look-up support with exemptions and multiple possible actions upon positive results
Line 67: Line 62:
   * Synchronet's normal host filtering (via ''ip.can'' and ''host.can'') and configurable LoginAttempt tracking/throttling/blocking (in ''[[config:sbbs.ini]]'') is also employed   * Synchronet's normal host filtering (via ''ip.can'' and ''host.can'') and configurable LoginAttempt tracking/throttling/blocking (in ''[[config:sbbs.ini]]'') is also employed
  
-==== DNSBL ====+=== DNSBL ===
  
 DNS-based Blacklists (DNSBL) are 3rd party databases of IP addresses whose hosts are suspected of being habitual spammers or have other security problems which make mail received from these systems highly suspicious. Different DNSBL services/servers have differing criteria for what can get an IP listed or de-listed (removed) from their database. Examine your ''[[dir:ctrl]]/[[config:dns_blacklist.cfg]]'' file to determine what DNSBL services your Synchronet Mail Server is using. DNS-based Blacklists (DNSBL) are 3rd party databases of IP addresses whose hosts are suspected of being habitual spammers or have other security problems which make mail received from these systems highly suspicious. Different DNSBL services/servers have differing criteria for what can get an IP listed or de-listed (removed) from their database. Examine your ''[[dir:ctrl]]/[[config:dns_blacklist.cfg]]'' file to determine what DNSBL services your Synchronet Mail Server is using.
Line 86: Line 81:
 When a DNSBL service reports an IP address as "black-listed", any additional DNSBL services/servers are not queried. When a DNSBL service reports an IP address as "black-listed", any additional DNSBL services/servers are not queried.
  
-=== Exemptions ===+== Exemptions ==
 MTA's whose IP address or hostname is listed in your ''[[dir:ctrl]]/dnsbl_exempt.cfg'' file are never checked against DNSBL servers. MTA's whose IP address or hostname is listed in your ''[[dir:ctrl]]/dnsbl_exempt.cfg'' file are never checked against DNSBL servers.
  
Line 100: Line 95:
  
 {{:server:SBBSCTRL.mailsrvr.advanced.png?400|}} {{:server:SBBSCTRL.mailsrvr.advanced.png?400|}}
-===== External Mail Processors =====+==== External Mail Processors ====
 FIXME FIXME
  
-===== ListServer ===== +===== SendMail ===== 
-FIXME+ 
 +The Synchronet Mail Server's //SendMail Thread// is responsible for delivering Internet email using the SMTP or ESMTP protocols, optionally authenticating using PLAIN, LOGIN, or CRAM-MD5 SMTP-AUTH methods if required by an SMTP relay server. 
 + 
 +Both Direct Delivery and Relaying (e.g. through intermediary mail server) is supported. 
 + 
 +The SendMail Thread currently can service one outgoing SMTP/ESMTP session at a time. 
 + 
 +The SendMail Thread will attempt to deliver securely (encrypted via TLS) when possible, though it will fall back to plain text delivery when necessary. 
 + 
 +===== Post Office ===== 
 + 
 +The mail server also services authenticated "post office" requests from mail clients using the POP3 protocol, by default, on TCP port 110 and POP3S (Secure/encrypted POP3 over TLS) on TCP Port 995. 
 + 
 +The POP3 server supports client authentication via the USER or APOP methods. 
 + 
 +The POP3 server can service multiple simultaneous incoming sessions. 
 + 
 +For IMAP support, see Deuce's [[service:imap|IMAP Service]]. 
 + 
 +==== Anti-SPAM ==== 
 + 
 +The Synchronet POP3 server will filter-out SPAM-tagged mail automatically when a POP3 client logs in with ''//<username>//#nospam''. 
  
 +Append "#nospam" to your login name/alias and any
 +SPAM-tagged messages will not be listed/downloaded. This is useful if for
 +example you use POP3 to download mail to your phone and have limited
 +storage or sorting options. The SPAM-tagged messages will remain in your
 +inbox on the BBS so you should use another POP3 or local mail client to
 +download and delete those messages (which could potentially include
 +false positives).
  
 ===== See Also ===== ===== See Also =====

Trace: