Envelopes not feeding on the SendPro MailCenter

Learn how to resolve envelopes not feeding on your SendPro® MailCenter.
Products affected: SendPro® MailCenter 1000, SendPro® MailCenter 2000, SendPro® MailCenter 3000


Envelopes do not feed through the meter.


This issue can be caused by a number of factors:

  • The envelope dimensions are outside of the acceptable range.
  • The envelopes are not stacked properly on the feed deck.
  • The thickness adjustment knob setting is incorrect.
  • The stack of envelopes is leaning away from the feeder.
  • Too many envelopes are on the feed deck.
  • The envelopes are too heavy or too thick.
  • Belts or rollers are worn, damaged or missing.


  1. Ensure that the envelopes meet the specifications.
  2. Sort the mail by envelope size. All envelopes in a single stack should be the same size.
  3. Shingle the envelopes so the bottom envelope feeds first.
    Note: This is not necessary if your mailing machine runs in WOW mode.
  4. If your mailpieces are sealed, fan them to make sure they do not stick together as a result of previous processing.
  5. Place the stack of mail on the feed deck. Place the envelopes with the flaps down and against the rear wall.
  6. Make sure that the envelopes are pushed far enough so that they cover the feed sensor located on the feed deck near the rear wall.
  7. Adjust the side guide so that it is close to, but not touching, the bottom edge of the envelope stack. Be sure to leave a slight clearance between the side guide and envelopes (about 1.6mm clearance).
  8. Use the thickness adjustment knob to adjust for envelope thickness.
    • If envelopes do not get past the thickness adjustment knob, set it to a higher setting.
    • If too many envelopes get fed, set the thickness adjustment knob to a lower setting.
  9. If the feed motor does not start, clean the feed sensor at the back wall near the entrance of the meter.
  10. Using a can of non-flammable canned air and working from the left side of the meter to the exit, blow onto the feed deck that the envelopes / tape sheets travel on. Ensure that all dust and debris get removed.

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UPDATED: June 16, 2023