Hi Maxim,
Since the code in question should not run in Strategy Window mode at all, the only reasonable explanation might be having On Demand Data Update enabled.
A side note:
1. At any rate it's under your control. Follow suggestion in this FAQ:
Is there a way to profile Wealth-Lab 6 Strategies i.e. measure application/script performance?2. In some cases, an overhead could be caused by using System.Reflection but not in your case I think.
3. Per se, sending email implies a big time penalty. Sending 200 emails in a row in a sequential manner (or you risk getting banned by the SMTP server for concurrent connections - this may be treated like a form of spam abuse) should take minutes. If the SMTP isn't some paid service I'd even insert a delay between the calls!