This is one of the first expressions that I learnt when I started to write in Spanish. Clearly, it is very useful!
The key question here is how to convert this into English! I am sure most of you have a good idea but it is worth covering nonetheless.
The key point to highlight is that anything including the word "doubt" is not ideal because it is generally associated with something negative! So avoid it if you can! You don't want to imply that your customer is having "doubts" about you or the service you provide.
This translation is not good:
A much better version would be something like this:
Both of these options are a much more native approach to this sentence and clearly avoid a direct translation from Spanish!
I hope that helps! If you want to improve your business English a little more you can check out my book on Amazon!
Soy el director de Daniel Smith + Partners. Tengo más de 10 años de experiencia enseñando inglés a españoles.