I hope you've written an LOE to explain why the reference letter lacks detailed duties & responsibilities...
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i'm sure the case officers will face lot of such deficiencies as,if there is something so common about hr experience letters across globe,it is only that 'those lack in details
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so with the email from her which gives contact details etc brings in credibility to your situation...
I'm sure ppl reading ur post will surely let you pass through
....I hope and feel you should be alright.
It would have been a nice idea to collect a reference letter from a senior employee who has worked in the same company/office during ur term with all ur job details and get it notarized. ..I suggest,if you are so worried about the issue ,get one such letter notarized and submit through a CSE option....also scan his id/visiting card both side images as well.....