A customer reported this week that their Macs were suddenly all crashing when trying to send mail , reply or forward.  Which is odd.. until I found this technote with the following statement updated on April  1st

As of April 1, 2019, IBM does not recommend upgrading to 10.14.4 for customers running pre-Notes 10.0.1 releases (i.e. Notes 9.0.1.x).  We are currently working on resolving a crash issue that occurs after upgrading to this latest OS via SPR #ZNDNBAPSZB.  This is documented under TN #0879431.

TN #0879431 is dated April 2nd and says a fix will be provided soon.

If you’re having issues with Notes on Mojave 10.14.4 and you’re running a version prior to 10.0.1 you might want to consider upgrading or let’s hope HCL provides a fix soon.