Hi Adele;
Yes it will. However, SAP changed the MAPI behaviour in v12.6 to Extended MAPI as the default vs Simple MAPI that was used in earlier PB versions. This means that your "mail" PB commands may not work unless you have the correct MAPI protocol enabled.
Here is SAP's workaround in order to switch back & forth between Simple & Extended MAPI - click here.
Note that the above also applies to PB 2017 as its based on the v12.6 code-line.
HTH
Regards ... Chris