In truth I normally do both. I'll send an email flagging that there is a blocker I want to discuss at the next relevant opportunity.
And I've also found that writing that email leads to me solving the problem at least 50% of the times (same with writing to forum posts of StackOverflow questions)
And I've also found that writing that email leads to me solving the problem at least 50% of the times (same with writing to forum posts of StackOverflow questions)