When you send a memo based on Stationery, in some cases the Stationery is deleted from your mail file if the sent memo contains an attachment.
User created stationery is missing from mail file after use.
Resolving the problem
This behavior can occur if an anti-virus program used to scan Notes mail adds the extmgr_addins=nlnvp.dll parameter to the notes.ini file. When this parameter is not used, the stationery remains available in the Notes mail file.
Comment out or remove the extmgr_addins=nlnvp.dll parameter from the notes.ini file.
This was reported as SPR # JSTN8RKQUD which has been closed as a 3rd party (Symantec) issue.