bulk mail
Noun
Meaning
mail consisting of large numbers of identical items (circulars or advertisements) sent to individual addresses at less than 1st-class rates and paid for in one lot
Source: WordNetSynonyms
Hypernyms
Examples
As the pandemic worsens, mail usage is slowing down — particularly businesses have cut back on sending advertisements and bulk mail — and the USPS is quickly running out of money to supports its operations.
Yes the ballots are postage paid but the Post Office handles them as 3rd class bulk mail, meaning it is not expedited.