slow startup

[Kenichi Asai]

Dear Mutt experts,

I am using mutt in the following configuration without any problems.

Mutt 1.9.0 (2017-09-02), installed via homebrew
macOS Sierra 10.12.6 on Mac mini (Late 2014)

However, when I cloned the entire hard drive (using DiskUtility) to
MacBookPro (Mid 2012), mutt takes about 5 seconds before it displays
the initial list of e-mails.  (On Mac mini, mutt shows the initial
list of e-mails instantly after I launch mutt from the terminal.)
Even if I remove my muttrc file and hide all my e-mails, it takes the
same 5 seconds before mutt shows a blank screen.

Why does it take so long time to start up?  Have anybody had the same
experience?  What should I check?

My guess is that mutt automatically checks some machine or network
configuration and wait 5 seconds for time out before starting.  Does
mutt do such things?  How can I learn about them?

I have been using mutt for decades, but this is the first time to
experience such slow startup.

Any help welcome.  Thank you in advance.

Sincerely,

-- 
Kenichi Asai