Invalid Email – The format of the email address is incorrect (Eg. de@firstname.lastname@example.org)
Invalid Domain – The domain, which holds the second part of email address, is invalid or not working or the MX servers don’t resolve to correct mail server.
Rejected Email - The Mail Server has rejected stimulating email protocol. It may be because the server is not accepting any new emails temporarily or the IP we have used for connecting is degraded (highly unlikely)
Accepted Email - The Mail Server is accepting email to the desired recipient. It usually indicates that an email is valid and ok to send.
Low Quality - The email address is classified as low-quality email. You are less likely to get a good response from sending emails to the ones in this category. This could be because of a number of reasons including factors like the email belonging to a disposable domain.
Low Deliverability - Much similar to the low-quality emails. We believe the deliverability rate for emails in this category will be low. You are highly likely to get a lot of bounce-backs.
Cannot Connect - Happens when we are unable to connect to the mail servers. Usually, happens when the timeout is maxed or if the mail server is too busy to respond back. Trying again after a while should help correct this problem.
Timeout - When we cannot connect to mail server in specified amount of time. We have different timeout periods for different SMTP we connect to. This implies the mail server is too busy to process our request at this time. It is best to try again later.
Invalid SMTP - Occurs when the mail server responds with codes that are foreign. It implies there is something wrong on the connecting end. We cannot do anything about invalid responses that SMTP servers output time to time.
Unavailable SMTP - Occurs when the SMTP server is unavailable to process our request. It is advised to try again after a while.
Unexpected Error - Similar to Invalid SMTP error where we didn't get back a response that is usually expected to be returned. It occurs rarely and you should contact our team to help us investigate further.