Adds the attachment pattern to the collection of attachment patterns.
The attachment pattern is a string (like !filename!) which denotes a placeholder to be replaced with the actual attachment filename during mail merge operation. When Replace method is called with the value of pattern parameter equal to the filename pattern previously added with AddAttachmentPattern method, the file denoted by the path specified in actualValue parameter of Replace method will be automatically attached.
Note Pattern of the message template is case-sensitive! For instance, if the pattern is #filename# and the attachment patterns contain #FILENAME# and #filename#, then only #filename# will be replaced with the actual value.
The example is available in MailMerge class overview.
MailMerge Class | MailBee.Mime Namespace | ClearAttachmentPatterns