Not all outgoing SMTP mail servers were created equal, and how much email you can send each hour  or each day will be determined by the particular outgoing SMTP mail server that you use to relay your messages.

Each ISP, web hosting, and free email provider establishes its own email sending policy which outlines specifically how much email you can send through their outgoing SMTP mail server per connection, per hour or per day. These hourly and daily email sending limits are established independently and vary from one email provider to another.

Why do ISPs, web hosting and free email providers have email sending limits?

Hourly and daily email sending limits are not nefarious. They exist simply to control the level of email traffic being processed, to ensure that the mail server will be available to support all of its users whenever they need to send email and to prevent spam from being sent through their system. Not unlike speed limits on highways, byways and motorways around the world, email sending limits establish a control to keep everything moving along smoothly.

“What will happen if I send more email per hour or per day than my ISP allows?”

If you send more email per hour or day than permitted by the email sending policy of the ISP, web hosting or free email provider you are using to relay your messages, the most likely result will be that your messages will simply start to fail after the hourly or daily limit is reached. When this happens, you will receive some sort of timeout error stating that “…you have reached your daily sending quota…” and you will usually have to wait for a period of 24 hours before sending more email through that mail server.

If you look closely, it will be obvious that the errors are related to sending limits set by the outgoing mail server, because the emails will start to fail after a round number of messages were sent successfully (perhaps after 100, 250, 500, 1000, etc.)

If you continuously try to send more email than allowed, your reputation as a sender will be affected and ultimately, the host could block your account from sending due to abuse. So, work with your mail server, not against it.

If you are using GroupMail to send your group email, you will see these send message errors from the outgoing mail server appear in the Delivery Console during sending and they will appear in the General Status Log for the message.

“Is there a way to get around the hourly or daily email sending limits of my ISP?”

If the outgoing SMTP mail server of your ISP, web hosting or free email provider has and email sending policy with hourly or daily email sending limits that do not support the size of your mailing list, there are several things you can do. For example, you could purchase your own dedicated web server, use a secondary SMTP relay server or use group email software that includes an internal SMTP engine like the one available via Direct Send mode in GroupMail.

For details about how to send more email, read email send limits and options.

ISP Email Sending Limits

Comcast Email Sending Limit

– Residential customers: 1,000 emails per day
– Business customers: 24,000 emails per day
– 10mb per email limit
Comcast email sending guidelines

Verizon Email Sending Limit

– 100 recipients per email (Bcc:)
– 500 emails per hour
Verizon email sending guidelines

AT&T Yahoo Email Sending Limit

– 100 recipients per email (Bcc:)
– 20mb per message
AT&T Yahoo email sending guidelines

BellSouth Email Sending Limit

– Open to the discretion of BellSouth
– Senders should contact with requirements
– 10mb per message
BellSouth email sending guidelines

RoadRunner Email Sending Limit

– 1,000 emails per day (per IP)
– 5mb per message
RoadRunner email sending guidelines

Earthlink Email Sending Limit

– 1,000 recipients per day
Earthlink email sending guidelines

Cox Email Sending Limit

– No limits published by Cox.
Cox email sending guidelines

Cox states that “Specific email sending limits are not published because they vary from time to time depending on a variety of factors”. Senders are advised to contact Cox prior to sending high volume email campaigns.

Optimum (Cablevision) Online Boost or Online for Business Email Sending Limit

– 50 recipients per message (Bcc:)
– 20mb per message
Optimum (Cablevision) email sending guidelines

Charter Email Sending Limit

– 50 emails per hour
– 10mb per message
Charter email sending guidelines

Web Hosting Provider Email Sending Limits

GoDaddy Email Sending Limit

– 250 emails per day
– Option to purchase additional GoDaddy SMTP relays
– 30mb per message
GoDaddy email sending guidelines

LunarPages Email Sending Limit

– 200 emails per hour on shared Windows environment
– 400 emails per hour on shared Linux environment
– Also offer a dedicated email server plan with no limits
LunarPages email sending guidelines

RackSpace Email Sending Limit

– No limits for messages complying with the RackSpace Acceptable Use Policy.

iPowerWeb Email Sending Limit

– 500 emails per hour
– 5,000 emails per day
– 25mb per message
iPowerWeb email sending guidelines

1and1 Email Sending Limit

– 1 message ever minute with a 10 second pause between messages.
– or use Bulk Send Mode in GroupMail – 1 message with 55 recipients every minute.
1and1 Help Centre

 Bluehost Email Sending Limit

– 500 emails maximum per hour
– Contact Bluehost to arrange for extension on the default limit
– 10mb per message
Bluehost email sending guidelines

Homestead Email Sending Limit

– 10 emails per second
Homestead email sending guidelines

20i Stackmail Sending Limit

– 8,000 messages per 24 hours
20i Email policy

Free Email Provider Email Sending Limits

Google Gmail Email Sending Limit

– 500 emails per day when sending from their web interface
– 100 emails per day when sending from a desktop email client
– 10mb per message
Gmail email sending guidelines

Windows Live Hotmail Email Sending Limit

– 100 emails per day
– 10mb per message
Windows Live Hotmail email sending guidelines

Yahoo Email Sending Limit

– 100 emails per hour
– 10mb per message for Yahoo
– 20mb per message for Yahoo Plus
Yahoo email sending guidelines

� AOL Email Sending Limit

– 100 recipients per email (Bcc:)
– 500 emails per connection
– 16mb per message
AOL email sending guidelines

What if the email sending limits of my ISP or web hosting company do not support the size of my mailing list?

If the hourly or daily email sending limits of your outgoing SMTP mail server do not support the size of your mailing list or the frequency of your email campaigns, there are options to send more email each day, such as using a secondary SMTP mail server relay or email software with an internal SMTP engine like the one behind GroupMail’s Direct Send mode.

For more information about the options available to send more email than allowed by your current outgoing SMTP mail server, read Email Send Limits and Options.