
We noticed the following:
When we send an email from the issued reminder to a customer with the languate ENU of ENG, then the subject of the e-mail is written in the language which we have selected in my settings.
In My settings our language is set with the value Dutch (Netherlands).
When we want to send an issued reminder, then the subject of the e-mail is: <companyname> - Verzonden aanmaning AAN00001
When change our language in my settings to English (United States) and we want to send the reminder again, then the e-mail is having the following subject:
<companyname> - Issued Reminder AAN00001
If we send a posted sales invoice with our language set on Dutch (Netherlands) and the language of the customer is set on ENU, then the subject of the e-mail will automatically be in the language of the customer and not the settings in my settings.
We prefer to have the same when sending an email of an issed reminder as of the posted Sales Invoices.
I reviewed the setups for reminders and there are no language options.
I recommend that you report either as a bug or as an idea.