Many companies fear diversifying their content into multiple languages because they don't have the infrastructure, or don't know how to set up the infrastructure to support it. It's much easier than most think to support multi-lingual applications and it comes down to having the right systems in place and multi-lingual support.
Just because your app is in multiple languages doesn't mean you need to provide customer support for those languages. For smaller applications, it makes sense to start with a disclaimer on languages outside the primary languages which states it contains translated content and that your application's customer support is only supported in the main language. Typically, it takes a solid year for the search engine optimization to drive large amounts of traffic to the website for new languages. Only once you have driven more traffic to the site in a specific language, you can consider adding support for that language.
Using API webhooks like Zapier or IFTTT, you can easily integreate automatic email translation for any emails that are received in non-primary languages. Despite stating that customer support requests must be in one particular language, we've found that customers will still prefer to email and contact customer support in their main language. Perhaps this is so that their inquiry doesn't get lost in translation (pun intended).