Hi,

   Here is an example for managing employee documents and their expiry   Document Expiry         

Hi,

You can do the same in different ways,

1. Automated Action : In the database make sure that the module named base_automation installed, then after activating the developer mode in the Settings -> Technical -> Automation -> Automated Action , here you can create a record for sending the email during the visa expiration . In the model you can set the corresponding model, in the action to do field select Send email option and set Trigger Condition as Timed Condition.

2. Other way is to use the custom addons available for the same in the Odoo app store,

      * Visa Expiration Notification By E-mail                                                                                                                        

      * Employee Documents

The first module is for the v8, if you are using the higher version, you can either port it to higher version or refer its code. The second module is a general one, which can be used for any documents. Create a document as Visa attach the Visa and set the expiry date. The notification will get send on the expiry date or before it.

Thanks