Whitelisting Replicon emails.
Find resources designed to help you get the most from Replicon
Email servers are usually configured to black list emails from unknown senders, or from invalid domains due to threat of spam. This may block emails from Replicon Web TimeSheet considering it to be spam.
White listing the IP addresses of Replicon on the mail servers will help to avoid the emails being marked as spam.
Below listed details can be used to white list Replicon's emails.
Reference for white listing the IP address on Exchange server 2003: https://technet.microsoft.com/en-us/library/cc875815.aspx.