I am not getting time sensitive Spirit emails on time since March. For example I got the T-24 check in reminder only 3 hours before the flight last month. Yesterday I made a new booking and the confirmation email arrived today.
EDIT: Found Gmail option to see the SMTP headers (Postmarked by each mail server as the message gets handed over), and it is delayed by Spirit Mail server, Spirit mail server contacted Microsoft mail server the next day.
Received: from omptrans.fly.spirit-airlines.com (129.145.67.220) by VI1EUR06FT029.mail.protection.outlook.com (10.13.7.190) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6340.21 via Frontend Transport; Tue, 25 Apr 2023 15:52:23 +0000
Received: by omptrans.fly.spirit-airlines.com id ... for <.. [MENTION=765869]hot[/MENTION]mail.com>; Mon, 24 Apr 2023 09:39:40 -0700 (envelope-from <
[email protected]>)