You can customize the URL scheme Hook uses with different applications by editing the Get Address script associated with an app in Preferences>Scripts
I modified this Get Address script to use the link format message://
Try it out and let me know if it does what you’re asking for.
tell application "Mail"
set frontWinIsMessageViewer to false
set fid to id of front window
repeat with v in message viewers
set wid to id of window of v
if fid = wid then
set frontWinIsMessageViewer to true
end if
end repeat
if frontWinIsMessageViewer then
try
set theSelection to selection
set theMessage to item 1 of theSelection
set mid to message id of theMessage
set mid to my encodeText(mid, true, false)
return "message://%3C" & mid & "%3E"
on error eStr number enum
--display dialog eStr & " Number: " & enum buttons {"OK"} default button 1
return
end try
end if
try
set theSelection to selection
set theMessage to item 1 of theSelection
set mid to message id of theMessage
set subj to subject of theMessage
set wname to name of front window
set astid to AppleScript's text item delimiters
set AppleScript's text item delimiters to {" ", ": "} -- to strip "re: ", "re:", "Re: ", "fwd:", etc
repeat with i from 1 to count of text items of subj
repeat with j from 1 to count of text items of wname
if text item i of subj is equal to text item j of wname then
repeat with k from j to (count of text items of subj) - i
set window_title to text item k of wname
set subj_name to text item (i + k - j) of subj
if window_title is not equal to subj_name then
set AppleScript's text item delimiters to astid
return
end if
end repeat
set AppleScript's text item delimiters to astid
set mid to my encodeText(mid, true, false)
return "message://%3C" & mid & "%3E" -- an old message
end if
end repeat
end repeat
set AppleScript's text item delimiters to astid
on error eStr number enum
--display dialog eStr & " Number: " & eNum buttons {"OK"} default button 1
end try
try
set searchText to name of front window
set astid to AppleScript's text item delimiters
set AppleScript's text item delimiters to {" — "} -- to strip " — mailbox"
set searchText to text item 1 of searchText
set AppleScript's text item delimiters to astid
set matchText to paragraphs of (do shell script "mdfind \"kMDItemSubject == " & quoted form of searchText & "\"")
if matchText ≠ {} then
set targetMatch to (item 1 of matchText) as rich text
if targetMatch ≠ "false" then
set lns to paragraphs of (read targetMatch)
# Loop over lines read and copy each to the clipboard.
repeat with ln in lns
--display dialog ln
if ln starts with "Message-ID:" then
set x to length of "Message-ID:"
set ln to characters (x + 1) thru -1 of ln as string
repeat while ln begins with " "
set ln to characters (2) thru -1 of ln as string
end repeat
repeat while ln begins with "<"
set ln to characters 2 thru -1 of ln as string
end repeat
repeat while ln ends with ">"
set ln to characters 1 thru -2 of ln as string
end repeat
set ln to my encodeText(ln, true, false)
return "message://%3C" & ln & "%3E"
end if
end repeat
end if
end if
on error eStr number enum
--display dialog eStr & " Number: " & enum buttons {"OK"} default button 1
end try
end tell
on encodeText(theText, encodeCommonSpecialCharacters, encodeExtendedSpecialCharacters)
set theStandardCharacters to "abcdefghijklmnopqrstuvwxyz0123456789"
set theCommonSpecialCharacterList to "$+!'/?;&@=#%><{}\"~`^\\|*"
set theExtendedSpecialCharacterList to ".-_:"
set theAcceptableCharacters to theStandardCharacters
if encodeCommonSpecialCharacters is false then set theAcceptableCharacters to theAcceptableCharacters & theCommonSpecialCharacterList
if encodeExtendedSpecialCharacters is false then set theAcceptableCharacters to theAcceptableCharacters & theExtendedSpecialCharacterList
set theEncodedText to ""
repeat with theCurrentCharacter in theText
if theCurrentCharacter is in theAcceptableCharacters then
set theEncodedText to (theEncodedText & theCurrentCharacter)
else
set theEncodedText to (theEncodedText & encodeCharacter(theCurrentCharacter)) as string
end if
end repeat
return theEncodedText
end encodeText
on encodeCharacter(theCharacter)
set theASCIINumber to (the ASCII number theCharacter)
set theHexList to {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "A", "B", "C", "D", "E", "F"}
set theFirstItem to item ((theASCIINumber div 16) + 1) of theHexList
set theSecondItem to item ((theASCIINumber mod 16) + 1) of theHexList
return ("%" & theFirstItem & theSecondItem) as string
end encodeCharacter