I'm probably going to word this poorly, but here goes.
I've created an SSIS Package with an email proceedure. It is supposed to send three emails, each one based on a SQL query.
The email tasks run sequentially, as part of the reporting requirement (An automated run is required daily, but sometimes one of the three emails needs to be sent manually. In those cases the other two Data Flow Tasks are disabled)
Heres where things get fishy. I can run the task from the editor, and no issues arise. Results: 3 emails, limited latency. These are relatively small queries (~50k records). When the task is run from Windows Task Scheduler, I get two of the three emails (notably the first two in the sequence), and quite a bit of latency (~10 minutes total execution, ~ 3 minutes between emails.) Latency isn't concerning me, but the missing email is.
The task is set to expire if it runs longer than 12 hours, so timeout is unlikely the cause. I'm tearing my hair out trying to figure this out!
Note: to make things more interesting, I recompiled the script executing all three email (script) tasks in one data flow task. Same behaviour there, with a very interesting twist. Every time I complied the bianries with three email tasks I got a two emails
Example:
Compile 1 -> Load into Windows Task Scheduler
Result -> Lab & IT email
Compile 2-> Load into Windows Task Scheduler
Result -> Base & IT email
The heck?