ITA Networks offers separate solutions for corporate and home users and there is a significant difference in their capability for reducing spam from users INBOX. Refer to the image below that explains the differences at a very high level. In case of ITA Secure Messaging Web Service, provided by RFSS.COM messages get filtered after they come into your INBOX. New messages are checked every 30 minutes. Therefore, it is very likely that a user checks his/her messages before ITA Secure Messaging gets a chance to clean the INBOX. When this happens user will see these spam message in their email reader and ITA Secure Messaging will never know about it, hence we cannot guarantee a 99% accuracy rate. Other differences Although how messages are filtered is the most prominent difference between ITA Secure Messaging Corporate and the Web Service, here are a few more. Sender IP The IP address of the sender may not be always correct. Although every message header contains the IP address of the sending SMTP server, the order in which these IP appear is not guaranteed. Therefore, IP based filtering can produce unwanted results. SPF lookup SPF lookups are not possible because the IP Address as well as Smtp MAIL TO command are not available. Bayesian Analysis Due to resource constraints Bayesian analysis is not done in web service. BCC recipients are lost Blind carbon copy (BCC) recipients are removed from the email header once an email messages comes into a users INBOX. Therefore, there is no way to find out who the actual recipients were. Reporting The Corporate Edition of ITA Secure Messaging includes extensive reporting capabilities that does not exist in the RSFF service. Richer rule set The Corporate Edition of ITA Secure Messaging includes additional rules and filters that are not found in RSFF.com. Some of these rules are very important in determining if an email is spam or ham. However, due to limited resources on RSFF.com, these rules have not been included.