System Limitations

The following list represents the most important limitations in the PostalMethods system. Other limitations may apply, but will usually not have an impact on users. Please note that this list may change over time.

For any specific questions, please email


Control Panel

  • Mail information in the Activity table is kept for: 45 days.
  • Mail images (View Mail) are stored and visible for: 14 days.
  • Partial mail information is kept in the Account > Billing Details > Activity list for: 90 days after a prepaid card was depleted.

Mailing Web Service API

  • Allowed “Get” method requests: one every 6 seconds per method.
  • Maximum number of pre-uploaded files: (20) If you require more, please email
  • Pre-uploaded files are stored for: 1 year after they were last used. The file’s last usage date is updated when it is used to send mail.

Administration Web Service API

  • Maximum number of users per account: 20 (default). If you require more, please email

Images and Documents

  • Maximum and recommended Postcard Image properties: 3750 pixels by 2700 pixels at 600 DPI. The image size would be 4.5″ by 6.25″ at 600 DPI.
  • Minimum image resolution: 300 DPI. Lower resolution may not look sharp when printed.
  • Maximum file size: 2MB for the generated letter or postcard PDF.
Send Letters
Securely + Reliably
Send letters securely and reliably from any business application. Use for invoices, quotes, and other important business communications. Enjoy special web-form to postal features and instant notifications.
Simple Process
Easy as 1-2-3
Experience the ease of our streamlined process - developed for efficiency! You submit your document by email or API. We automatically print, collate, insert, and stamp your letter. Your letter is delivered via standard postal service.
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Register for free with no obligations! Evaluate the service as long as you need. Once you are ready, set up our user-friendly pay-as-you option to use our service. No fuss. No on-going commitment. Just plain easy!