Founded in 1889, the NALC is the union of city letter carriers employed by the U.S. Postal Service, and they are upset about Donahoe's proposition to end Saturday delivery in August as a cost-cutting measure for the service.
NALC rallies took place across the country Sunday, including one in Jackson that was attended by Cleveland letter carrier Sherrie Crain and about 75 fellow supporters.
"We're fighting to keep the Post Office alive," said Crain. "We don't want it to go away and that's what will happen if we get rid of Saturdays.
"Dismantling services will be the beginning of the end. People will eventually have to find somewhere else to get their mail delivered."
Donahoe contends cutting out Saturdays would save the Post Office $2 billion a year, but Crain argues the move would hurt the service and communities in the long run.
"Everything would roll downhill if Saturday mail is cut," said Crain. "About 80,000 carriers would lose jobs, then it would be clerks and next local businesses would start suffering.
"In our community — a rural area — it's even more important. People need the communication the Post Office provides."
She added there's a lot of confusion about the real financial status of the Postal Service, especially in reference to a required $5.5 billion yearly payment toward pre-funded promised healthcare benefits for retirees for the next 75 years — something no other public or private agency does.
Since 2006, Congress has required the service to provide the pre-funded benefits, and in 2012, it defaulted on its annual payment for the first time.
There was little backlash when Congress originally established the system, but at that time, the economy was in a much healthier condition.
"The Post Office is not as broke as it sounds," added Crain. "What we need to do is convince Congress to get rid of this mandate and focus on ways to bring in more money."
Providing next-day delivery, increasing package options, boosting products and services and maintaining a six-day delivery schedule are just a few of her suggestions for improvement.
"People don't know the whole story. We need to get back to days of when the Post Office was making a profit," she said.
Rallies held across the country backed some of Crain's sentiments.
Postal workers, customers and family members walked around downtown Gulfport Post Office with signs Sunday afternoon in support Saturday delivery.
"Five-day is not the way. Stop the mandate to pre-pay," said Greg White, leading them in a chant as they walked along U.S. 90 and up U.S. 49 to the Post Office.
White is state president of the Mississippi Association of Letter Carriers.
"This is not a protest," White said. "It's a rally to help save the post office."
According to the NALC website, on March 20, the U.S. Senate approved its version of a continuing resolution to mandate six-day mail delivery.
The House passed the measure on March 21 unchanged, and it now goes to President Obama, who is expected to sign it into law.
This will only preserve Saturday mail by law through Sept. 30.