There are two causes for this problem.
1. The generic Email server has strict limitations on file size of attachments. If the software sends all captured screenshots, the file size will exceed the Email capacity and as a result the email cannot be sent successfully.
2. Considering the actual speed of network, if the email is large enough which may delay the sending time and thus leading to failure to send the email.
The amount of monitored screenshots to send is generated based on the attachment size limit of free emails and the screenshots size on the monitored computer, and then averagely taken from the all screenshots captured in the specified sending time, which basically guarantees the completeness and integrality of monitored screenshots.
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