Deliver official mail found in mail collection boxes to the local OMM for further disposition.  The OMM must  return  the  official  mail  to  the  office  personnel who put the mail in the ordinary mail collection box. The  OMM  should  then  decide  if  office  personnel dealing  with  official  mail  require  further  training  in official mail procedures. POSTMARKING Official  mail  bearing  postage  stamps  must  be postmarked along with ordinary outgoing mail. Do not postmark  mail  deposited  after  the  last  scheduled collection until the following day.   Postmark missent official  mail  on  the  back  to  show  the  date  received before dispatching it to its final destination. SORTING Official  mail  is  sorted,  bundled,  and  dispatched with  other  outgoing  mail.    Handle  official  mail  the same  as  other  outgoing  ordinary  mail,  provided  the official mail has no registered mail or special services added.    As  previously  discussed,  registered  mail  is handled with more security than ordinary mail. Incorrect sorting or pouching of mail will result in mail delays.  Strict adherence to proper procedures is of   utmost   importance   and   will   help   prevent unnecessary mail delays. MAIL CLASSIFICATION The class of mail service selected for Navy official mail  should  meet  the  security,  accountability,  and delivery requirements of the material being shipped at the lowest possible cost. Compute the postage and fees for domestic mail according to the DMM. Use USPS Poster 123 with the Postal Zone Chart for the post office to which the item will  be  mailed.     Figure  the  postage  and  fees  for international mail according to the IMM, and USPS Poster  51.    Properly  programmed  electronic  scales may be used to compute postage and fees. Items mailed from one overseas MPO to another overseas MPO in the same theater must have the words DOD  Official  Intra-Theater  Mail  placed  in  the  area where the postage is usually affixed.  The words DOD Official Intra-Theater Mail can be typewritten, rubber stamped, or mechanically printed. First-Class  Mail  may  be  used  for  mailing  the following:    Official handwritten or typewritten material    For  items  required  by  USPS  regulations  to  be sent  at  the  First-Class  rate  of  postage  (refer  to Module R of the DMM for weight restrictions)    Material less periodicals (including newsletters) and  newspapers,  that  cannot  be  mailed  more economically at a lower class or rate of postage Priority   Mail   may   be   used   for   mailing   the following:    Official handwritten or typewritten material    Items required by USPS regulations to be sent at the Priority Mail rate of postage (refer to Module R of the DMM for weight restrictions)    High-priority  shipments,  such  as  non-mission capable  supplies  (NMCS),  partially  mission capable  supplies  (PMCS),  casualty  report (CASREP),   ships’  essential   equipment requisition expediting program mission capable (SEEREP MICAP), 999, or other items critical to flying and marine safety    Material  mailed  under  the  Uniform  Material Movement   and   Issue   Priority   System (UMMIPS)  priority  designators  01  through  08 consigned to addressees located more than 300 miles from the sender    Shipments of supply issue group I or II material consigned to mobile units and overseas activities served by FPO or APO addresses Official  mailings  not  qualifying  as  Priority  Mail and weighing more than 13 ounces must be endorsed and sent as Standard Mail (B).   Standard Mail (B) is matter  weighing  more  than13  ounces,  not  mailed  or required  to  be  mailed  as  First-Class  Mail,  and  not mailed  at  the  Periodical  rate  of  postage. Official mailings  not  required  to  be  mailed  First-Class  or Priority  Mail,  and  not  exceeding  70  pounds  or  108 inches in length and girth combined, must be endorsed and sent as Standard Mail (B). Official   mailings   having   a   critical   required delivery  date,  but  do  not  qualify  as  First-Class  or Priority Mail and are destined for addresses outside of the United States (including Alaska and Hawaii) may be sent as military ordinary mail (MOM).  In addition to the class of mail endorsement (Standard Mail (B)), this  mail  must  have  the  abbreviation  MOM  boldly rubber-stamped  or  printed  on  the  address  side  of  the mail container. 13-17