QuickMail: messages not showing in history

3 quickmail messages were sent in succession, within a fairly short time frame but these messages were never showing in QuickMail history.

• the QuickMail history was not reset
• the messages were not deleted manually
• the QuickMail block was not deleted and/or restored
• messages do not show up in the database
• the emails were actually sent (showing up in SMTP logs)
• some older messages are showing up in the history for the same user