At least the CSV import creates a mail domain object automatically if a user with an unknown domain part within its email address is created. This can lead to severe problems in mail routing. The automatic creation of mail domain objects should be disabled for the CSV import and (if also affected) in the schoolusers module.
Looks like the CLI import script does the same but the creation of the mail domains may be controlled via ucsschool/import/generate/mail/domain. This should also be the case for the ucs-school-lib.
Fixed in ucs-school-lib 5.0.44-1.148.201405221514 No changelog needed
works as expected → VERFIED
UCS@school 3.2 R2 has been released: http://docs.univention.de/release-notes-ucsschool-3.2R2-de.html If this error occurs again, please use "Clone This Bug".