Bloomington mail processing annex
The Bloomington Mail Processing Annex is a mail sorting facility serving the whole region surrounding Bloomington for many miles. All mail gathered from or to be delivered to zip codes beginning 474xx comes through the Bloomington MPA. This zip code range includes all of Bloomington (47401-08) as well as all communities at least as far as Spencer, Bedford, French Lick, Nashville and so forth (south of Martinsville, however).
It is not a post office, and does not generally see the public. Mail should be delivered to a regular post office or mailbox. There is a mailbox outside the facility that has the last pickup time in the region to get postmarked or in that day's mail, 6 pm M-Sat.
There is currently some controversy about whether the Bloomington MPA should be partially or wholly consolidated into the Indianapolis PD&C mail processing center. The city council has passed a resolution favoring the continued function of the 474 MPA as is.
A biased source advocating the continuation of the MPA instead of consolidation: Postal Workers Union.
Explanation of mail processing in 474xx