When an SMTP conversation is dropped or fails, there are two primary types of codes. If the command was accepted or rejected by the MTA, it is indicated by the first number in the code. The reason for the failure is indicated by the two numbers that remain in a code. The categories of codes are:

Too many Failed Attempts Gmail

https://supporrt-18883030822.medium.com/too-many-failed-attempts-gmail-88155350e2db