Recommender sent me letter to submit I am applying for postdoc positions this fall, and have three references.
My main two writers are doing everything as I expected.
The third agreed to write a letter for me--and he wrote a very good letter. It was very positive and I was even impressed by how personal it was, given that we do not know one another all that well.  He is also very well-known/famous in the field.  However, he simply gave me the letter to use as I wish, so it won't be customized for each position or anything.
I do not really have any good sense of what to do with this, when I apply for postdocs.
My PhD advisor said that he agreed it was strange, but &quot;I would keep the letter and when requested send it and say he sent it to you.&quot;  I am just not sure what the least awkward way to do this is.
(I want to add: both my advisor and I are quite certain this letter will help my case.  My first two letters are going to be great, and are written by people who know me very well and will be tailoring, etc.)
Should I simply include, after the contact information for two references on my CV, &quot;An additional letter of recommendation from ________ is available by request.&quot;?
Edit after some exchange in the comments below: I recommend that you contact the writer of the third letter and tell them that what you really need is them to send the letter directly when asked, and to pass on contact details now. This problem seems to be the result of a misunderstanding, and busy high profile researcher or not, if a misunderstanding is happening, it makes sense to clarify things. If you don't get a response, you can still use the letter you have.
Original answer:
Personally I wouldn't have worried about simply including the letter. What's wrong with that? It's a good letter, and if they don't believe it is genuine they can contact the writer. Where I work, such letters are not that important anyway. Personally I'm fine if a candidate is able to present two or three such letters by qualified people in which there is nothing worrying, and that's it. As most candidates fulfill that, these letters play no further role in decision making (frankly even unsuitable candidates can come up with glowing reference letters, so these are not that informative; even some high profile people write nice letters for everyone). Of course I can't guarantee it's like that everywhere.