How to Increase Attachment Size Limit to 35 MB for Emails Received via Shared Mailbox

[Akhila P]

Hi Community,

I’m working on a requirement where users send emails with attachments to a shared mailbox, which will create an RITM. I need to support attachments up to 35 MB, but I’m not sure how to configure this.

Could anyone guide me on:

1. How to increase the attachment size limit in ServiceNow?
2. Are there specific system properties I need to update?
3. Any best practices for handling large attachments through email?

Appreciate any help or suggestions!

Thanks,
Akhila Prasanna Pajjuri!

[Misgana D Dauro]

Hi @Akhila P ,

Check this system property glide.email.inbound.max_total_attachment_size_bytes.  Two things to note though:

updating this record could impact performance and also this record will be skipped during your instance upgrade.

If my answer has helped with your question, please mark my answer as an accepted solution and give a thumbs up.

Kind regards

Misgana D.

[Ankur Bawiskar]

@Akhila P 

so there is an incoming email which has attachment and it should be allowing upto 35MB?

I believe OOTB the combined attachment size on incoming email is 18MB controlled by this property "glide.email.inbound.max_total_attachment_size_bytes"

You can increase that but it will have performance impact

Email body/attachment size limit system properties 

💡 If my response helped, please mark it as correct ✅ and close the thread 🔒— this helps future readers find the solution faster! 🙏

[Me Being Mustaq]

Hi @Akhila P ,

You may find below thread helpful:

• How to adjust the maximum allowable size of an attachment to a record - Support and Troubleshooting
• Email size limits

Best Practices for Handling Large Attachments via Email

1. Validate File Size Early:
   Use business rules or inbound email action scripts to check attachment size and reject or notify users if limits are exceeded.

2. Inform Users:
   Communicate attachment limits clearly to users sending emails to avoid frustration.

3. Use Compression:
   Encourage compressing large files before email submission to reduce size.

4. Monitoring & Performance:
   Large attachments impact database size and system performance—monitor storage growth and clean up old attachments regularly.

5. Consider Alternative Upload Methods:
   For very large files, consider requesting users upload attachments via secure file transfer or Service Portal instead of email.

If it is helpful, please hit the thumbs button please mark the answer as correct based on the impact!!

Kind Regards,

Shaik Mohammed Mustaq