Currently the old web hosting (plesk) hosts the domain, website and email service for my employer. To use the email service, some of the employees use outlook (use POP to download email), some of them simply setup redirect (to their personal mail box), nobody use the horde webmail web interface.
There is a new website which is built on a new web hosting (directadmin). To switch to this new web hosting, if I re-create all the email accounts in directadmin, then ask the old webhosting to change the NS record pointing to the nameserver of the new web hosting.
During the DNS propagation, for those who use outlook, there may still be some incoming emails sent to their inbox on the POP server of the old web hosting.
After the propagation is completed, can they still click the send/receive button in the outlook as usual to download these emails from the POP server of old web hosting, before they change to the email server setting of the new web hosting in the outlook?