If an email that you have specified as the recipient is undeliverable, you will automatically receive a message about it (SMTP Error 5xx). The error code gives you an indication of the cause (e.g. 'User unkown' or 'Address rejected' mean that the receiving email server does not know the address).
yve receives the bounce message in parallel through the so-called 'postmaster copy'. If a receiving server doesn't send the 'postmaster copy' or uses non-standard formats, yve won't be able to process the bounce.This e-mail will then be automatically blocked to prevent the wrong email addresses from being sent. Please check the email and correct the email recipient. You can simply re-send it to a changed email address. You can get a list of all blocked contacts by setting the 'Bounced' filter on Contacts. In the detail participant report, the status is displayed in the column 'Email Status'.
If you believe that the reason for the bounce of an email has been resolved, you can unblock the email in the contact details of the participant with 'unblock email'.
Important: Receiving email servers detect spammers by how many undeliverable e-mails a sender has generated in a given time period. If this number exceeds a threshold, the sender will be blacklisted and all e-mails from this sender will no longer be accepted, even if they are valid addresses.
To prevent this from happening for yve as a sender, yve will automatically cancel an email as soon as a certain threshold of undeliverable emails is exceeded.
Please keep your emails so that the rate of undeliverable emails does not exceed 5% and the rate of the complaints is not 0.1%. If this value is exceeded repeatedly, your account can be blocked.
There are services that verify email addresses for you without causing reputational damage (for example, https://www.email-validator.net
). There you can upload your email addresses and verify them for a small fee.
If you have set up your own email gateway, yve will not receive any bounces and therefore cannot block any emails. If you have set up your own MAIL FROM, emails that were first accepted by the receiving email server and then later reported as a bounce to the MAIL FROM address cannot be recognized by yve as a bounce and are therefore not blocked.