The connector fetches multiple mails in one connection to the IMAP server for efficiency, instead of using one connection per mail, which would be much slower.
These mails are loaded in the memory of your JVM (Java Virtual Machine), which can lead to out-of-memory errors. If this problem occurs:
• Lower the Max. fetched size property, all the while increasing the Max. fetched mails to avoid losing too much performance. However, if an email's size is bigger than the Max. fetched size, it is not indexed and a warning is issued in the connector log.
• If possible, increase the memory allocated to the JVM.
Mails Do Not Group by Thread Subjects
Depending on the mail server, it happens that emails from a same thread are not grouped all together.
To tackle this issue, you can activate the Subject normalization option to group mails with the same subject. For more information, see Subject Normalization .