Before starting the update process, make sure you backup your files and database, this is very important.
The upgrade process:
Make sure you download latest version of AppMail and you don’t use the files from the same version you already have installed. AppMail archives are numbered properly, like appmail-X.Y.Z.zip where X.Y.Z is the version number to which you will be upgrading to.
Unzip the archive that contains the AppMail application. In it you’ll have two folders: update and latest. You’ll need the update folder.
1. Make sure you are not running any campaign when updating (pause them if needed)
2. Move your application offline from Backend -> Settings -> Common
3. Upload the contents of the “update” folder on your host, overwriting (don’t replace, but overwrite) the existing AppMail files (the ones which you initially uploaded to install the app)
4. Follow the update wizard
After the upgrade is done, make sure the needed folders are still writable by the web server. if you’re not sure what folders must be writable by the web server.
NOTES:
Some FTP clients, such as Transmit for macOS(x) will replace your server files with the ones from your local folder. This is not the correct behavior, because the client will delete the files from the server then upload the ones from your local folder.
The correct behavior is to override existing files with the new ones, so please pay attention to the way the files are actually uploaded.