@blonsterkathryn wrote:
I think it's a "hit and miss" type thing. I admit, I have shipped a few "lot" listings of magazines via media mail (they are extremely heavy when in a "lot"), with no problem. Keeping my fingers crossed. It's a huge market that the post office is definitely losing money on. Such is life.
You could look into library mail.
https://pe.usps.com/text/dmm300/173.htm#ep1113500
5.2 Qualified Mailings Between Entities
The items described in this section may be mailed at the Library Mail price when sent between: (1) schools, colleges, universities, public libraries, museums, and herbariums and nonprofit religious, educational, scientific, philanthropic (charitable), agricultural, labor, veterans, and fraternal organizations or associations; (2) any such institution, organization, or association and an individual who has no financial interest in the sale, promotion, or distribution of the materials; or (3) any such institution, organization, or association and a publisher, if such institution, organization, or association has placed an order to buy such materials for delivery to itself:
- Books, consisting wholly of reading matter, scholarly bibliography, or reading matter with incidental blank spaces for notations and containing no advertising, except for incidental announcements of books.
- Printed music, whether in bound or sheet form.
- Bound volumes of academic theses, whether in typewritten or duplicated form.
- Periodicals, whether bound or unbound.
- Sound recordings.
- Other library materials in printed, duplicated, or photographic form or in the form of unpublished manuscripts.
- Museum materials, specimens, collections, teaching aids, printed matter, and interpretive materials for informing and furthering the educational work and interests of museums and herbariums.
