Since the olden days of the Internet, email has been sent over SMTP (Simple Mail Transfer Protocol). SMTP assumes that the receiving computer is always online (has a connection to the Internet). With the rise of Internet users whose computers are not always online, a number of SMTP alternatives have been devised.

The acronym bSMTP stands for batched Simple Mail Transfer Protocol. This saves emails that come in for you until they can be delivered. If your mail server is online and it connects to the VEVIDA mail servers, email messages will be delivered immediately over SMTP. When your mail server is not online, email messages are stored by VEVIDA and delivered as soon as your mail server makes a connection.
Options for email accounts, aliases and mailing lists will be discontinued at VEVIDA.
One key benefit of bSMTP (compared to POP3/IMAP) is that you can create an unlimited number of email addresses. This way, a company can give each employee his/her own email address. New email addresses can be added and used without intervention on the part of VEVIDA.

Configure bSMTP

To prepare your mail server for Batched SMTP (bSMTP), you can read the bsmtp and sendmail mini-how to. This explains how to set up Sendmail (8.9) for use with a Linux system that is not online 24 hours a day, 7 days a week. The document gives special attention to using Sendmail with a bSMTP account, as offered by VEVIDA.
Other options include Microsoft Exchange, MDaemon, etc.

You can use the ETRN command. This is not strictly necessary because every time our mail server receives a signal on port 25/tcp from your IP address, it starts relaying email as soon as it receives the QUIT command.

If you are having problems configuring Exchange (5.5/2000/2003), you can use the dequeue.exe (direct download) tool.
You can use this tool and the Windows Scheduled Tasks to have the email retrieved (for instance, once every 15 minutes), the full command line is:

C:> dequeue.exe bsmtp.example.org -p 25 -d example.org

From the Windows command prompt cmd.exe, you can use the telnet command, possibly even in combination with the Windows Scheduled Tasks and/or a .cmd file. In this case, the command is:

echo quit | telnet bsmtp.example.org 25

It is possible to push email forwarding using the following shell code in a crontab on a Linux/Unix system. Replace example.org with your own domain name.

#!/usr/bin/expect -f
spawn telnet {bsmtp.example.org} 25
expect
{
  timeout exit
  "ESMTP"
}
send "etrn {name}r"
expect
{
  timeout exit
  "started"
}
send "quit"
close

With following optional code:

send "etrn {name}r"
expect
{
  timeout exit
  "started"
}

If Perl is installed on the server system (Windows, Linux, Unix), the following Perl script can be used. Simply connecting to port 25 will suffice.

#!/usr/bin/perl
# --------------------------------------
use strict;
use Socket;
my $smtp_server = 'bsmtp.example.org';
my $servername = $smtp_server;
my $proto = 'tcp';
my $port = '25';

if ($smtp_server ne "") {
  my($proto) = (getprotobyname('tcp'))[2];
  my($port) = (getservbyname('smtp', 'tcp'))[2];
  my($smtpaddr) = (my $smtp_server =~
      /^(d{1,3}).(d{1,3}).(d{1,3}).(d{1,3})$/)
      ? pack('C4',$1,$2,$3,$4)
      : (gethostbyname($smtp_server))[4];
  if (!defined($smtpaddr)) {
    print "SMTP host unknownn";
    exit();
  } if (!socket(MAIL, AF_INET, SOCK_STREAM, $proto)) {
    print "socket() on ".$servername ." failedn";
    exit();
  } if (!connect(MAIL, pack('Sna4x8', AF_INET, $port, $smtpaddr))) {
    print "connect() on ".$servername ." failedn";
    exit();
  } else {
    print "connect() on $servername succeeded!nE-mail should arrive shortlyn";
    exit();
  }
}
# --------------------------------------

Please see your confirmation email for the exact details. The data given on this page, such as the host name, are merely examples.

Tips

  • If you have to select from IMAP/POP3/SMTP/ESMTP for incoming mail, choose ESMTP.
  • For the domain, enter your domain name, for instance: ‘yourdomain.com‘.
  • Only accept email for your own domain. Do not relay any emails addressed to other domains. Better yet, do not accept any emails at all that are addressed to other domains. If you do, then your mail server can be used by others for purposes such as spamming (sending unsolicited emails).

Information on turning off undesired relays in different mail server applications is available at http://www.mail-abuse.com/support/an_sec3rdparty.html.

Microsoft Exchange/Small Business Server and Active Directory networks:

If you request batched SMTP from VEVIDA and you have an Active Directory (AD) domain/network, please take the following into account:

  • Do not give your internal AD network the same name as your domain (example.org) when there is a clear separation between the internal network (LAN) and the Internet. Use a name with “.local” or “.lan”, for instance, as a (non-existent) top-level domain. The reason for this is: An AD server (DC, or Domain Controller) also serves as a name/DNS server for the LAN. If the correct DNS zone records were not created in your own Active Directory, then you will not be able to visit your website and your SBS server will not receive any emails. The host name bsmtp.example.org (for instance) does not exist according to your own DNS server.
  • If there is no clear separation between the LAN and the Internet, choose a name like “lan.example.org”. In MYVEVIDA, you can create the “lan” subdomain and have it point to your own (external) IP address.

We strongly recommend that users of systems like Microsoft Small Business Server 2003 check that they have installed the KB835734 update.

502 unimplemented (#5.5.1) , 459 service unavailable

If the ETRN and/or QSND commands are used, it is possible that the following error message will appear in the MTA (mail server program) log files:

502 unimplemented (#5.5.1)
459 <domainname.tld>: service unavailable

This error message is generated because our servers do not recognize commands ETRN or QSND. However, you do in fact need to enter the command in your MTA because otherwise you would not be able to connect to the VEVIDA mail servers.

When is bSMTP not possible?

Batched SMTP is not possible if your access provider has blocked port 25/tcp incoming on the network. First contact your access provider and enquire whether this is the case; some networks block access to port 25/tcp from the outside.

Please Note

The way bSMTP works is that first all email comes in on our mail server, and the email is not sent until your own mail server asks for it. In your request, always give the external IP address for your mail server.

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