Custom Inbox Errors

Adding an inbox for sending in Quickmail depends on the type of email account. Unlike Gmail and Outlook inboxes, adding Custom Inboxes can be more tricky as it requires manually setting up the IMAP & SMTP Settings. 


Depending on the email provider or how IMAP & SMTP Settings of the inbox are set up, some issues may be encountered when adding an inbox. Here are the usual errors and how to fix them:

Error: Network error: Unexpected token < in JSON at position 0

Reason 1: Wrong Port Number, Credentials, or Server Address used.

  • Try changing the port number (We only support TLS & SSL)
  • Make sure that the login credentials used are correct. Some email provider requires generating a special password when using third-party apps.
  • Check help articles or reach out to your domain provider to verify if correct Server address is used. 

Reason 2: IMAP Settings is not enabled. 

  • Some email provider requires a paid subscription for IMAP. Make sure that IMAP settings are enabled. 

Reason 3: Email account has too many folders.

  • When we test the IMAP, we look for a certain message ID by searching all folders in the inbox. It usually takes .5 seconds to iterate over each folder. If we won't be able to iterate over each folder within 30 seconds, it will lead to an error. So to fix this, we suggest reducing the number of folders in the email account to no more than 59 folders or less

UID SEARCH Backend error

Reason 1: This is a known error that's coming from Yandex's IMAP server.

  • Apparently, there's no fix provided yet by Yandex. Reach out to Yandex to look for a new possible fix. 
  • A workaround to add an inbox from Yandex is to add it as a Gmail or Outlook inbox. This can be done by signing up for a Gmail or Outlook account and use the email address bought from Yandex. 

Unknown Mailbox: [Gmail](now in authenticated state)(Failure)

Reason 1: We have Gmail integration. Gmail inboxes can't be added by manually setting up IMAP & SMTP settings

  • To add a Gmail inbox, simply sign in using Google. 

  • If there's a need to use different SMTP settings, add the inbox by signing in to Gmail first, and then set up a custom SMTP. 

    Here's a guide on how to set up a custom SMTP: