I am about to go back to Brighthouse and leave Verizon as they have a limit of 500 emails in an hour. If I send out 5 emails to everyone on my contact list I am over and get blocked. I am tired of this as it makes me have to be very selective of who I send emails too. I only go on once a day to send out emails and I have many that I like to forward to friends and family. I never had this problem when I was with Brighthouse, I pay for email service and it should be my business how many I chose to send.
They are trying to combat the problem of spam. Although it may be inconvenient to log on several times a day to send email they are just trying to protect as many users as possible.
Brighthouse also limits you.
You can send email to 1,000 recipients per day per IP on the outbound email servers - See more at: http://support.brighthouse.com/Article/Outbound-Email-Policy-Road-Runner-1687/#sthash.J3vE5Z5I.dpuf
Verizon limit is 500 an hour or 12,000 a day.
Similar limits are on many of the email providers.
Businesses and Organizations can get a different level service. Pretty much no ordinary user gets near such limits.