Mailroom Helpful Tips

Overstuffed Letters

Letters should not contain more than 8 sheets of paper, tri-folded. Documents inside envelopes should not be folded more than 3 times. Envelopes that are overstuffed are bulky with uneven content distribution. Overstuffed envelopes get stuck or ripped open in high-speed processing machines. All overstuffed envelopes need to be sealed by the sender. A template measuring tool is available free from the ADOA mailroom.


Foreign Letters Mixed With Domestic Letters

Outbound mail is processed by high-speed equipment that applies domestic postage to envelopes. Mail going out of the country has to have additional postage. Please flag (with a Post-It) or separate mail with foreign addresses to avoid delays. 


Handwritten Addresses

Outbound mail is processed with high-speed equipment that electronically reads addresses and sorts. Electronic eyes have difficulty reading handwritten addresses and will reject the envelope. These letters need to be hand sorted and can cause delays.


Ink Color

Black or blue ink should be used when addressing envelopes. 


Stamped Letters & Non-Stamped Letters Mixed Together

When a stamped letter is mixed with non-stamped letters it will go through the processing machines with non-stamped letters and postage will be applied on top of the stamp. Stamped letters will be paid for twice costing your agency money. Please flag or separate stamped mail.


Unsealed Flats & Stamped Letters 

All mail larger than a standard letter must be sealed by the sender. Stamped mail does not go through machine processing, it is the sender's responsibility to ensure that all stamped mail is sealed. 


Flats With Metal Clasp

Flats that have metal clasps or ties must be sealed. The clasp or tie must be taped over so they will not jam in automated machines. It is best to use envelopes without metal clips or ties. 


Mail With Binder Clips Or Paper Clips 

Mail with paper clips or binder clips either inside or outside can get jammed in the equipment and cause damage/ delays. Do not mail items with binder clips or hard inflexible items.


Writing Or Graphics Below Mailing Address

High-speed processing machines sort outbound mail according to region and zip codes. These machines are set up to read the bottom line of the address on an envelope. If something such as “Attention XYZ” is written below the City, State, Zip, or has other graphics below, the letter is rejected by the sorting equipment as it is unable to read the destination. This has to be hand sorted which causes delays.  







Cardboard Envelopes 

Cardboard envelopes are expensive and can not be presorted.  A good alternative is to use a 9”x12” envelope with a piece of chipboard to protect the certificate or other items that can not be folded.  This will help save postage.


Bulky Items In Envelopes 

Bulky items should be mailed in a box or a padded envelope. Things like flash/thumb drives, CDs, or cords get jammed in processing equipment and can rip open or be damaged by the equipment. 



The maximum size of a postcard is 6 inches long by 4 ¼ inches high. The postage side of a postcard should have a non-glossy finish so that postage ink will adhere. In order to receive presort postage rates there should be no writing or graphics below the address.  


Personal Mail

Personal mail must have postage applied by the sender as ADOA can not affix postage to such items. Personal mail should be mailed to a USPS blue box or Post Office. 


Envelope Color  

All envelopes should be white. Mail processing equipment is often times unable to scan dark-colored envelopes. 


Mail Surface 

Stay away from items with glossy surfaces. When the mail processing equipment applies postage it will smear on the glossy surface making it unmailable. 


Landscape Orientation 

Please mail all items in a landscape format. Large letters that are in portrait format are more expensive to mail due to the non-standard arrangement.


Disorganized Mail

Mail should be organized in the mail tubs and letters should be “nested” if unsealed. Flats and other large mail must be sealed by the sender. This allows mail to be processed quickly and keeps the contents of envelopes contained. Disorganized mail thrown into the bin can lead to contents spilling out. 


Other Tips & Tricks:

  • Avoid staples, paper clips, or other items that may poke out of envelopes. These items will jam in mail processing equipment or can injure mail carriers who handle the items. 
  • Labels affixed to letters and parcels should adhere to the item. Be sure the labels are sticky so they do not fall off easily during handling.  
  • If mail is flagged with a Post-it Note the note should stick above the rest of the envelopes in the mail tub.
  • Recycle! All mail, with windows, glossy, magazines, and various color paper is recyclable!
Document Type