Incoming mail does not arrive External e-mail users may send messages to mailboxes on your MailSite server that never arrive. There are a number of reasons why this happens, but it is typically related to errors in DNS configuration.

All internet SMTP servers rely on MX, A and CNAME DNS records to route mail. If your e-mail address is joe@abc.com, then when someone sends a message to you, their server will refer to the DNS records for abc.com to determine where to send the message. You can check your DNS records using NSLOOKUP:

• Open a command window
• Type: nslookup
• Type: set type=mx
• Type: abc.com (where abc.com is your domain name)
• NSLOOKUP should respond with a list of Mail eXchange (MX) hosts for your domain
• Your MailSite server should be listed as the primary record (lowest preference)
  
• If NSLOOKUP does not respond with valid MX records,
• Type: set type=all
• Type: abc.com
• If NSLOOKUP does not return any records: Contact the administrator of your DNS server and have the records created

If the DNS records are correct for your MailSite server, then remote machines may have trouble connecting. To debug this further, ask someone using a remote computer (such as your ISP) to run through the following procedure:

• Open a command window
• Type: telnet mail.abc.com 25 (where mail.abc.com is the host name of your server)
• TELNET should respond with something like: 220 abc.com MailSite SMTP Receiver Version 7.0.3 Ready
• If it does not, Type: tracert mail.abc.com
• This command will return a TCP/IP path through which you connect You should be able to identify the point at which your connection fails
• Report this information to your Upstream Provider

Other areas to check:

• Ensure the message is not being blocked by any sieve filters, either on the server, domain or mailbox level
• Ensure the account in MailSite does NOT have the 'don't deliver to this mailbox' option checked.
• Ensure the account in MailSite is not forwarding mail to another account
• Check for aliases.
• Turn on Operation Log Flags > SMTPRA > Protocol Exchanges logging to file log. This will help proove if the message is making to the MailSite server.