Overwrite email templates
If you want change the content of emails which are sent during an order you need to overwrite the give templates/partials.
        EXT:sitepackage/ext_localconf.php
    
$GLOBALS['TYPO3_CONF_VARS']['MAIL']['partialRootPaths']['1588829281'] = 'EXT:sitepackage/Resources/Private/Partials/';
$GLOBALS['TYPO3_CONF_VARS']['MAIL']['templateRootPaths']['1588829281'] = 'EXT:sitepackage/Resources/Private/Templates/';        
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The files need then to be placed in a directory named Mail.
The following tree view shows an example how the overwrite the mail template which is used when sending an email to the customer (=buyer) when the order is not payed yet ("open"). Furthermore the address partial is overwritten.
        Treeview under EXT:sitepackage/Resources/Private when using the above given configuration in 
ext_localconf.php  
    ├── Partials
│   └── Mail
│       └── Address.html
└── Templates
    └── Mail
        └── Open
            └── Buyer.html        
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