If order doesn't matter (i.e. just exclude all emails with an md5 in the exclude file) and you're not wedded to awk, use join:

join -v 1 -j 1 <(sort emails) <(sort excludes) 

-v 1 tells it to print lines in the first file (emails) that don't have a corresponding line in the second file (excludes).
-j 1 tells it to only look at the first column of each.

If you want to use awk, I believe this should work:

awk 'NF==1{exclude[$1]++} NF==2&&!exclude[$1]' excludes emails 

Or if the two files are lobbed up and you only want to exclude, e.g. line 2 if both have the same hash on that particular line, use this:

awk 'NF==1{hash[FNL]=$1} NF==2&&hash[FNL]!=$1' excludes emails 

If order doesn't matter (i.e. just exclude all emails with an md5 in the exclude file) and you're not wedded to awk, use join:

join -v 1 -j 1 <(sort emails) <(sort excludes) 

-v 1 tells it to print lines in the first file (emails) that don't have a corresponding line in the second file (excludes).
-j 1 tells it to only look at the first column of each.

If you want to use awk, I believe this should work:

awk 'NF==1{exclude[$1]++} NF==2&&!exclude[$1]' excludes emails 

Or if the two files correspond line-by-line and you only want to exclude, e.g. line 2 if both have the same hash on that particular line, use this:

awk 'NF==1{hash[FNR]=$1} NF==2&&hash[FNR]!=$1' excludes emails 

If order doesn't matter (i.e. just exclude all emails with an md5 in the exclude file) and you're not wedded to awk, use join:

join -v 1 -j 1 <(sort emails) <(sort excludes) 

-v 1 tells it to print lines in the first file (emails) that don't have a corresponding line in the second file (excludes).
-j 1 tells it to only look at the first column of each.

If order doesn't matter (i.e. just exclude all emails with an md5 in the exclude file) and you're not wedded to awk, use join:

join -v 1 -j 1 <(sort emails) <(sort excludes) 

-v 1 tells it to print lines in the first file (emails) that don't have a corresponding line in the second file (excludes).
-j 1 tells it to only look at the first column of each.

If you want to use awk, I believe this should work:

awk 'NF==1{exclude[$1]++} NF==2&&!exclude[$1]' excludes emails 

Or if the two files are lobbed up and you only want to exclude, e.g. line 2 if both have the same hash on that particular line, use this:

awk 'NF==1{hash[FNL]=$1} NF==2&&hash[FNL]!=$1' excludes emails