Message Handling System (MHS) is an important early email protocol developed by Action Technologies, Inc. (ATI) in 1986. Novell licensed it in 1988 then later bought it.
A wide variety of email clients used MHS, including:
MHS was a very 'open' system, and this, with Novell's encouragement, made it popular in the early 1990s as a 'glue' between not only the proprietary email systems of the day such as PROFS, SNADS, MCI, 3+Mail, cc:Mail, Para-Mail and Microsoft Mail, but also the competing standards-based SMTP and X.400. However, by 1996 it was very clear that SMTP over the Internet would take over this role.
A compatible family of products from Infinite Technologies (now Captaris) and marketed under the name Connect2[2] were also very widely used as part of MHS-based email networks.
Novell became increasingly less supportive after their 1994 purchase of WordPerfect as they worked to transform WordPerfect Office into GroupWise.
At about the same time, confidence in the future of X.400 collapsed and SMTP email across the public internet became the compelling choice for mail between unrelated organisations, replacing MHS's former "glue" role.