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Important Announcements

Cisco Secure Email Add-Ins No Longer Supported on Microsoft Outlook 2019

This is to inform you that, effective October 14, 2025, Microsoft Outlook 2019 is no longer supported for the Secure Email Encryption Service Add-In and Secure Email Submission Add-In.

To continue using these Add-Ins, we recommend upgrading to Microsoft 365. Starting October 2025, download and install the new manifest for:

- Secure Email Encryption Service Add-In from the CRES Admin Dashboard

- Secure Email Submission Add-In from the Cisco Software Download Portal

After downloading the manifests, follow the instructions provided in the Submission and Encryption Add-In guides. For more information, see: Cisco Email Encryption - End-User Guides.

TLS 1.0/1.1 Deprecation from AsyncOS for Secure Email Gateway, Starting version 16.5

We would like to inform you that starting with the AsyncOS 16.5 release, TLS versions 1.0 and 1.1 will no longer be available as configuration options in both the CLI and GUI.

To ensure secure email delivery and receipt, you should use TLS versions 1.2 and 1.3. These versions can be configured via the sslconfig CLI command or through the System Administration > SSL Configuration menu in the user interface.

For detailed instructions on updating TLS versions, please refer to the “System Administration” section of the User Guide for AsyncOS 16.0.x for Cisco Secure Email Gateway.

 

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Migrate from Secure Email Virtual C100V to Avoid McAfee-Related Issues

  Important: Migrate from Secure Email Virtual C100V Models to Avoid McAfee-Related Issues Dear Valued Customer, We are reaching out to ensure your Cisco Secure Email environment continues to operate at optimal performance and reliability. As worklo...

dmccabej by • Cisco Employee
  • 882 Views
  • 2 replies
  • 0 Helpful votes

Resolved! Ipcheck Values /esa

Hello guys,I was curious about the below values:Root 400MB 68%Nextroot 400MB 86%Var 400MB 3%Log 179GB 6%DB 2GB 0% Can someone please elaborate what each value means? when we should be alert about that?I see that the next root is 86% in my case at my ...

spacemeb by • Level 1
  • 2298 Views
  • 8 replies
  • 10 Helpful votes

Removing Received Headers on ESA

Hi,I had a look at this kb: How do I stop the ESA from adding a received header to my outgoing email messagesIs it correct it will only prevent to add the Received header at the ESA step. All "Received" headers added by the Exchange servers will stil...

REJR77 by • Level 1
  • 1924 Views
  • 0 replies
  • 5 Helpful votes

Resolved! Bounce by Destination Server

When we try to send an email to the specific user we get this message "5.1.0 - Unknown address error 550-'5.1.10 RESOLVER.ADR.RecipientNotFound; Recipient not found by SMTP address lookup"But the recipient able to receive the message in another test,...

Ah15 by • Level 1
  • 14429 Views
  • 6 replies
  • 0 Helpful votes

Resolved! (No sender) on ESA/SMA

Hello,We have received multiple messages some of them were malicious in which we could not see the sender's domain.Instead of the sender we had the (no sender) entry.Have you any idea where this is coming from? is it a bug ? or normal behavior under ...

spacemeb by • Level 1
  • 3123 Views
  • 1 replies
  • 10 Helpful votes

End of support for ESA version)

Hi community,Where can we find the date for the End of Support of ESA release (13.5 fo instance)?This one is about 12.5 (https://www.cisco.com/c/en/us/products/collateral/security/email-security-appliance/eos-eol-notice-c51-743742.html) Kind regards 

REJR77 by • Level 1
  • 864 Views
  • 2 replies
  • 5 Helpful votes
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