Here’s a quick list of the top 22 problems that you may need to troubleshoot with Exchange, and how to do them. Our hope is that this quick list, thick on fixes but thin on words, may help you in the future when you run into a problem and need to fix it right there and then!
Mail Delivery, Relay, and Delay
- Cannot do internal anonymous relay? See https://technet.microsoft.com/en-us/library/bb232021.aspx which is for Exchange 2010, but works on 2013 and 2016 too.
- Email sent to remote recipients is rejected because you’re a spammer? See http://mxtoolbox.com/blacklists.aspx and lookup both your domain and your ip.addr. If any of the blacklists show you as a spammer, this check will let you know, and provide more information on how to remove yourself from that list.
- Cannot establish SMTP/TLS-use TELNET to establish a connection to a remote SMTP server you know offers SMTP/TLS? Enter “EHLO example.com” at the prompt. You should get a 250 response listing several options, including STARTTLS. If you don’t see that, enter “MAIL FROM:email@example.com” and see if you get a warning response back. If you do, you’re probably on a blocklist. If you get a simple 250 2.1.0 Sender OK, then your own firewall is probably blocking SMTP/TLS.
- Confirming a firewall is in the way-use TELNET as above. If, instead of a banner, you see a 250 ******************** then your firewall is performing SMTP Fixup (aka Inspection) and you need to get your firewall admin to turn that off.
- Mail delivery is slow? Evaluate the SMTP headers once the message finally arrives to find which system caused the delay. Focus your troubleshooting efforts on that specific system.
- Use message tracking, built into Exchange, to figure out where delays exist or mail is being held up. It’s in the toolbox.
What’s that mean?
- Not sure what error 0x800c4005 means? Use the ERR tool, which you can download from http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=985
- There are lots of websites that document what the SMTP codes you see in network traces or even using TELNET mean. One of the most thorough is a PDF you can download from http://www.answersthatwork.com/Download_Area/ATW_Library/Networking/Network__3-SMTP_Server_Status_Codes_and_SMTP_Error_Codes.pdf.
- Exchange has specific DSNs and NDRs, and the Technet article at https://technet.microsoft.com/en-us/library/bb232118(v=exchg.150).aspx does the best job of explaining what they mean, with links to further documents which can help you troubleshoot the issue(s) causing the error.
Tools of the Trade
- The Exchange Remote Connectivity Analyzer at http://aka.ms/exrca has some great tools for testing everything from Autodiscover to EWS. It even has a simple SMTP header analyzer.
- Need to check your MX records from the outside world? Use http://mxtoolbox.com/ to do an external query.
- Want to see what’s going on with your email server from outside? Use http://centralops.net/co/ to run a test of your server to see DNS lookups, connections, response times, banners, etc.
- Need to be sure you’re not an open relay? Check out http://www.mailradar.com/openrelay/ which can run 19 separate tests against your server to ensure it won’t relay spam.
- Wonder if your SPF record is right? Test it at http://www.microsoft.com/mscorp/safety/content/technologies/senderid/wizard/
- Not even sure how to create an SPF record? Use the wizard at http://old.openspf.org/wizard.html to take care of that.
- Exchange server performance not up to snuff? Sure, you can use PerfMon to see if you have a resource issue, but first, try the Exchange Best Practices Analyzer to make sure your server is configured as it should be.
- If things are still slow, make sure your antivirus software is properly configured for Exchange. Overzealous scanning can adversely impact Exchange performance. Consult your antivirus software vendor for their proper settings when used with Exchange.
Mailbox and Client Side Errors
- Corrupt autocomplete cache? Use NK2Edit to edit the cache or wack it completely. http://www.nirsoft.net/utils/outlook_nk2_edit.html
- Strange errors in a user’s mailbox? See it the way Exchange does using MFCMAPI, downloadable from http://mfcmapi.codeplex.com/.
- Outlook has its own PST repair tool, scanpst.exe, that lives under your Office installation. Yes, even Outlook 2016 has this, as we all know PSTs are never going to go away.
- Things seem….”slow?” Take a look at the Connection Status for Outlook by simply CTRL+rightclicking (like that is “simple!”) to launch the Outlook Connection Status screen. Check latency and failed requests to see if there is a network issue, and also check the server (and proxy) name to be sure you are connecting to the right place.
- Third-party plugin blues got you down? Launch Outlook in safe mode (outlook.exe /safe) to disable all the extra stuff added to Outlook to see if that helps. If it does, disable them all, then reenable them one at a time to figure out which one kills your client.
We hope this list will help you quickly troubleshoot Exchange issues the next time you run into problems. Between the websites, tools, and approaches above, you should save some significant time running down the issue and getting things fixed, so you can get back to what matters.