1. Email shows delivered:

1.1 The email enters the spam folder, the recipient can go to the spam mailbox to check it.

1.2 The incoming mail server has not sent the email to the personal mailbox, the recipient can check the status of the email in the independent query of the incoming mailbox, and manually add the whitelist if there is this email.

1.3 The content of the email is of marketing nature and is automatically blocked by the system.

2. Mail shows undelivered, the following reasons are focused on

2.1 Recipient's format is not correct.

2.2 Recipient's mailbox is full or the remaining space can not accommodate the email you sent;

2.3 The recipient has rejected your email.

Solution: The same mailbox may sometimes be able to receive and sometimes unable to receive, if it is an enterprise mailbox, you can let the administrator of the enterprise mailbox whitelist the domain name of the Moka sender, the domain name of the Moka and the IP of the Moka sender can be requested through the online customer service and the customer success manager.