Allowing delegate access when mailbox owner and delegate are usingdifferent versions of outlook

[t]

Mailbox owner is using Outlook 2010 and delegate is using outlook 2007.
We do not have another license to move the delegate to outlook 2010 and
requested it from another office.

As per
http://office.microsoft.com/en-us/o...anage-your-mail-and-calendar-HA010075081.aspx


"You and the delegate must use the same version of Office Outlook."


Delegate has editor level rights to calendar of mailbox owner, though
she is using outlook 2007 and mailbox owner is using outlook 2010.
Delegate and mailbox owner are using Windows 7 professional(64 bit)


Is there a way access can be granted to delegate so she can send,
receive mails on mailbox owner's behalf without upgrading the delegate
to outlook 2010?