Tense agreement

As a British speaker I find the second version "incorrect".
BUT
The problem with this type of inquiry is that a "comparison situation" is not the same as a "judging a phrase in isolation". The first item implies the letter refers to a past state of mind, the second to an ongoing state of mind and either could be contextually valid. From that point of view different definitions of "grammar" come into play in which traditional prescriptive grammar takes "the sentence" as the focal element, whereas other grammars ( that of Halliday for example) take the whole discourse into account.

Thank you so much for your explanation, that was really helpful!