This article explains the attachment size limit for Acoustic Transact emails and available alternatives for sharing larger files with recipients.

Attachment size limit

The attachment size limit for Acoustic Transact emails is 0.5 MB per individual attachment. This is a fixed platform constraint and cannot be increased, regardless of your organization's configuration or support tier.

Why this limit exists

• Large attachments negatively impact email deliverability — many recipient mail servers reject or filter oversized attachments
• Large attachments slow down email send performance
• Large attachments consume excessive storage resources
• Attachments may exceed recipient mailbox quotas, preventing successful delivery

Alternatives for sending larger files

If you need to share files larger than 0.5 MB with recipients, consider the following approaches:

• Host files externally: Upload files to a secure web server or content delivery network and include a download link in the email instead of a direct attachment.
• Use cloud storage: Services such as Google Drive, Dropbox, or OneDrive can generate time-limited sharing links that can be embedded in your email content.
• Split large files: Divide large files into smaller segments that each fall under the 0.5 MB limit. Note that this approach may reduce the recipient experience.
• Use a dedicated file transfer system: For large or sensitive files, consider a secure FTP service or a dedicated file sharing platform outside of email.