FYI Outlook 2016 0x800CCC78

For the past few days when I was sending e-mail I was getting the error 0x800CCC78 with the message something along the lines of server returned 454.4.1.0 requested action aborted. I tested sending e-mail with Windows Mail and had no problem so I figure the problem must be with Outlook 2016. Looking up that error code on the Internet provided several suggestions and the suggestion that worked for me was using MicrosoftEasyFix 20101 to repair my PST file. Once I repaired the PST file I was able to send e-mail again.

I wonder what caused this corruption of my PST data file after many years of no such problem? Does anyone know if there is a size limit on the PST data file? I am guessing that is the cause of my problem. I have now reduced the size of my PST data file by 80% by allowing Outlook to archive my old messages. I will miss being able to easily search all my e-mail.

I think the limit for an outlook data file is 2 GB but I have had issues even before reaching that size. I believe that you can search an outlook archive file the same was the active data file. I think you just use the advanced search and specify the archive file to search. FYI I manually archived by creating an archive file by year and the just using the move comments to move messages are folders into the selected archive.

There are two format for PST. ANSI (97-2002) or UNICODE (Outlook Data File).
For ANSI (97-2002) size limit is 2 GB where as for UNICODE it depends on the version of Outlook you are using!

For Outlook 2003 and 2007, the max size is 20 GB. For Outlook 2010 and 2016, the max size is 50 GB.

Thanks for that information. I am using Outlook 2016 and my problems seem to have started when the size for the PST file was almost 1GB. I also had an archive PST file that was almost 1GB. MicrosoftEasyFix did find a few problems to fix; maybe that totally fixed all my e-mail problems but just to be sure, by manually archiving, I reduced the size of my PST file down to 250 MB.

Depending on your machine configuration, I found that once you reach about 12-13 GB on the PST, you start to have a little performance problem.
One of my friend reach that magic marker and complaint about slow response from Outlook 2013. I have him archive and reduce the PST to 7 GB. The performance problem disappeared.