The practice of capitalizing words in email subject lines involves varying degrees of capitalization, ranging from capitalizing the first word only, to capitalizing all words except for minor articles and prepositions, to capitalizing all words entirely. An example includes “Meeting Confirmation: Project Alpha Update” versus “meeting confirmation: project alpha update” versus “MEETING CONFIRMATION: PROJECT ALPHA UPDATE.”
Capitalization in subject lines can impact readability and perception. Historically, all-caps was sometimes used to denote urgency but is now generally perceived as aggressive or akin to shouting. Proper capitalization, mimicking title case, aims to increase clarity and draw attention to the message’s core content, potentially improving open rates. Conversely, sentence case (only the first word capitalized) may appear more informal and less demanding of immediate attention.