123 reg mail quota

A common question!

The "123" in "123 reg mail quota" refers to the maximum number of emails that can be sent from a single IP address (or "reg" stands for "registered") within a specific time period, usually 24 hours.

The "mail quota" part refers to the total number of emails that can be sent from that IP address within that time period.

In other words, if you have a 123 reg mail quota, it means you can send up to 123 emails from that IP address within 24 hours. If you try to send more than 123 emails, your email service provider (ESP) or the receiving email server may block your emails or flag them as spam.

This quota is usually set by email service providers (ESPs) to prevent spamming and to ensure that their servers don't get overwhelmed with too many emails.