Most of the Time issues can be narrowed by performing the simple approach. First of all collect the necessary information such as recipient mail address. Let's say the recipient mail address is John@Aol.com.Go to DNS Report.com and on the left upper cornet paste the mail address of recipient and perform the mail test, by clicking the mail test icon.
Wait for the results and look for SMTP error code. Come back to SMTP25.BlogSpot.com and look it up the error Code or Google it. Open your DOS window and perform Telnet session back to the recipient mail server, watch for response back from the mail server. AOL trouble shooting is easy just click the link below
Troubleshooting AOL E-mail Delivery
- Check all the possible reasons below, if you are having trouble to send mail to certain domains
- Make sure you have RDNS for your domain.
- Make sure you are not on the any of the RBL list
- Make sure you are not on Yahoo black list ( call yahoo)
- Make sure there is no Cisco Firewall issue (article id 828263)
Enable SMTP logging on your default virtual server.
To turn on Diagnostics Logging on the MSExchangeTransport service, follow these steps:
- Start Exchange System Manager.
- Expand Servers, right-click Your_ Server_Name, and then click Properties.
- Click the Diagnostics Logging tab, and then click MSExchangeTransport under Services.
- Under Categories, click the category that you want to log.
- Under Logging Level, click the appropriate logging level for the issue that you are investigating:
Note: to see event messages turn up the logging level to medium or high. Check to see if you receive the following event messages in Events viewer with event logging turned on. Make sure you do not have any antivirus software blocking the mails such as Symantec Antivirus, Enable Internet E-mail Auto-Protect" option.
- Add your external DNS into SMTP server properties ( I did not like this solution)
- Open your Exchange system manager-> Administrative groups->First Administrative group->Servers-Your Server->Protocols->SMTP->Right Click Default Virtual Server->Properties->Delivery->Press Advanced Button->Press Configure Button near the Configure external DNS servers->In The exchange 2k3 system attendant.
- go to Properties of Default SMTP Virtual Server
- Delivery Tab >Advanced button >Configure Button
- Now I added my ISP's 'Resolvers' not DNS servers (VERY IMPORTANT) and I moved one of theirs to the top...didn't work in second or third position for some reason.
- Stop and Restart Default SMTP Virtual Server.
Go to Queue and watched aol.com and yahoo.com roll on out....no reboot necessary
1. True DNS problems
- Firewall issue - UDP packet
- No external DNS - Use external DNS or 'Resolver' (not sure if that is correct)
- DNS server running slow or spotty and fails to return correct IP - (fix DNS server)
- user is rejected or all mail rejected (ensure that a PTR - reverse DNS entry is available for your Email server's FQDN)
2. Anti-Virus/Third party program
- Virus/Third party program's Smart host/DNS is not set correctly
- Specific Virtual SMTP server is not set to use Anti-Virus Smart host
3. Exchange problem
- DNS lookup returns MX record of a machine that does not respond, but exchange will not use the second MX record, and instead uses A record to get the IP. (work around - Use Smart Host so that multiple MX servers will be tried)
- b. DNS lookup fails due to unknown reason, and Exchange uses A record not MX record. (unknown)
4. Client Problem / Outlook issue
- signature causes problem somehow, believe or not
The final trouble shooting TIP is, upgrade your mail server to Exchange 2007 to make it robust (- :