BugZero | F5 BugID 515635 - Tcl monitor not working with Courier IMAP server

F5 - Defect ID: 515635

Tcl monitor not working with Courier IMAP server

F5 - Defect ID: 515635

Tcl monitor not working with Courier IMAP server

Last updated on July 18th, 2026

BugZero Risk Score
6.7 Medium

Overall: 6.7

Severity: 7.3

Community: 4.2

Lifecycle: 7.0

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Bug Details

Priority: 3-Major
Status: Verified
Impact Category: Local Traffic Manager

Description

Symptoms

Tcl monitor produces FTP error with Courier IMAP server.

Impact

IMAP monitor fails, potentially resulting in downed pool members. The systems posts an error similar to the following: ERROR: failed to complete the transfer, error code: 8 error message: FTP: weird server reply.

Conditions

Courier IMAP Server when there is no message in the mailbox.

Workaround

Add a message to the monitored mailbox.

Fix Information

IMAP TCL monitor now works without error with Courier IMAP server when the monitored mailbox is empty.

Change history

Links

Original Vendor Announcement

Relevant Products

Click on a version to see all relevant bugs

Affected versions:11.6.0, 11.6.0 hf1, 11.6.0 hf2, 11.6.0 hf3, 11.6.0 hf4, 11.6.0 hf5, 11.6.0 hf6, 11.6.0 hf7, 11.6.0 hf8, 11.6.1, 11.6.1 hf1, 11.6.1 hf2, 11.6.2, 11.6.2 hf1, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3, 12.0.0, 12.0.0 hf1, 12.0.0 hf2, 12.0.0 hf3, 12.0.0 hf4, 12.1.0, 12.1.0 hf1, 12.1.0 hf2, 12.1.1, 12.1.1 hf1, 12.1.1 hf2, 12.1.2, 12.1.2 hf1, 12.1.2 hf2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 12.1.5, 12.1.5.1, 12.1.5.2, 12.1.5.3, 12.1.6

Fixed versions: 13.0.0

Relevant Products

Click on a version to see all relevant bugs

Fixed versions: 13.0.0

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F5 - Defect ID: 515635

Tcl monitor not working with Courier IMAP server

F5 - Defect ID: 515635

Tcl monitor not working with Courier IMAP server

Last updated on July 18th, 2026

BugZero Risk Score6.7 Medium

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

F5 - Defect ID: 515635

Tcl monitor not working with Courier IMAP server

F5 - Defect ID: 515635

Tcl monitor not working with Courier IMAP server

Last updated on July 18th, 2026

BugZero Risk Score6.7 Medium

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

BugZero Risk Score
6.7 Medium

BugZero Risk Score
6.7 Medium