It was a conscious decision to add spaces between the commas,

fenner · fenner · commit 2c26d31933cc · 2007-06-15T16:56:00.000Z
to allow wrapping in case there are a lot of addresses.
 - Legacy-Id: 411
diff --git a/test/diff/_liaisons_321_ b/test/diff/_liaisons_321_
@@ -0,0 +1,5 @@
+--- https://datatracker.ietf.org/public/liaison_detail.cgi?detail_id=321 
++++ /liaisons/321/ 
+@@ -13,1 +13,1 @@
+-IETF CCAMP WG (adrian@olddog.co.uk,dbrungard@att.com)
++IETF CCAMP WG (adrian@olddog.co.uk, dbrungard@att.com)
