This function is only available for the Advanced plan.
You can securely send important emails by setting the security level when writing emails.
For the security level, only the levels permitted by the administrator are displayed among 'General', 'Restricted', and 'Confidential'.
For emails set as 'Restricted' or 'Confidential', they cannot be sent to an external address. When replying or forwarding, the previously set security level, expiration date, and forwarding option values cannot be edited or deleted.
If you select 'Restricted' or 'Confidential', you can set the expiration date and the option on restricting forwarding.
After the expiration date, the email is automatically deleted from the recipient's mailbox, and may also be deleted from the sender's mailbox depending on the administrator setting options.
If forwarding prohibited is set to use, you cannot forward emails received to others or add a new address when replying to selected people or all.
Security level settings
Mobile
- Tap
in the email you are composing. - Tap 'Security Level'. Depending on the content and importance of the email, you can select one of the following security levels: 'General', 'Restricted', and 'Confidential'.
- When you select 'Restricted' or 'Confidential', you can set the expiration date and whether to restrict forwarding.
- Valid period: The deadline on which you can check the email. Emails will be automatically deleted after the valid period. You can select among None, 1 day, 1 week, 1 month, 3 months.
- Forwarding Prohibited: Change the setting to make sure received emails cannot be forwarded to others.
- Tap 'Confirm'.
PC Web
- Click
on the top. - Click 'Compose' in Mail.
- Select a security level from the 'Security' field. Depending on the content and importance of the email, you can select one of the following security levels: 'General', 'Restricted', and 'Confidential'.
- When you select 'Restricted' or 'Confidential', you can set the expiration date and whether to restrict forwarding.
- Expires after: The deadline on which you can check the email. Emails will be automatically deleted after the set period. You can select among None, 1 day, 1 week, 1 month, 3 months.
- Forwarding Prohibited: Change the setting to make sure received emails cannot be forwarded to others.
Change the security level
You can change the security level of an email.
Mobile
- Tap 'Security Level' in the email you are composing.
- Select the level, valid period, and whether to prohibit forwarding and tap 'Confirm'.
PC Web
- Select the security level in the 'Security' section of the email you are composing.
- Select the valid period or whether to prohibit forwarding.
Delete the security level
Mobile
In the email you are composing, tap 
beside Security Level to delete the security level. After deleting the security level, you can set another one again.
PC Web
On the top of an email you are composing, click on the right side of the set security level value.