Thanks Victor.

>I'm not sure about any limits that outlook itself might have but I know there is at least one plug-in to do that:
>http://www.office-addins.com/-outlook-addins/batched-mail.html
>
>...anyway my guess is that the issue is probably either with your mail-server has a limit or perhaps your ISP does....and I suppose it's possible that even some anti-virus software could cause that problem too or even some anti-mailware software....
>
>>I'm sending emails through my app. to outlook with Craig Boyd's MAPI tool. In that particullar scenario I have to send 150 emails. This should become bigger and bigger with time.
>>
>>Nothing appeared in the Outlook outbox when sending all of the emails.
>>
>>I tested with one and everything's ok. I tested with 5 and still everything is ok.
>>
>>So from what I can understand there's some kind of limitation on the number of emails that can be sent on I guess a given time interval? Am I right? If I am what would be the quantity that can be sent at once? Does that mean that I would have to sent that given quantity (for example 30) and then wait for some time (How long ?) and then send another batch?