“I’m on retreat and will respond to messages after 7/6”

Abstract Previous studies have shown that dividing a broad register into sub-registers may reduce its internal variability. Building on this phenomenon, this study analyzes out-of-office emails, a sub-register of academic emails. We identify the communicative functions of 329 emails from 44 universities. We then describe the intra-register variability of the sub-register and use its situational characteristics along with politeness theory to help explain the observed communicative functions. We found 10 primary communicative functions, with return dates and expressions of gratitude being the most common. The sub-register appears largely internally consistent in that a majority of the emails relied on the same limited set of communicative functions. The (unknown) relationship among participants seems particularly helpful for understanding the functional strategies employed by the authors of these emails. Through this study, we hope to shed light on this overlooked sub-register and contribute to our understanding of intra-register variability.