IMAP activation is an asynchronous process which will take about 1-5 minutes. After activation you can set up your device or email client to access your account via IMAP.
Setting up IMAP access for Android 4.0.1 device
Go to Settings | Email
On the Account Setup screen type in your Inbox.com email address and password. Continue withNext.
Select IMAP as the type of account on the next screen
Set the IMAP server to imap.inbox.com, Port number to 993 and select SSL/TLS (accept all certificates) under Security type. Continue with Next.
Set the SMTP server to smtp.inbox.com, Port number 465 and select SSL/TLS (accept all certificates) under Security type. Continue withNext.
Under Inbox checking frequency select Every 15 minutes and keep all checkboxes checked
On the final screen, name your account, e.g. Inbox.com