I suspect that it is a custom bit of calligraphy (if you could provide more details as to the source, that would be helpful).

I got no hits by searching two large databases. The following fonts—some with alternate characters that replicate the swashes of the original sample—may be helpful in recreating the general look and feel:

http://www.myfonts.com/fonts/laura-worthington/Al-fresco/
http://www.myfonts.com/fonts/laura-worthington/alana/
http://www.myfonts.com/fonts/laura-worthington/hummingbird/
http://www.myfonts.com/fonts/trial-by-cupcakes/katie-rose/
http://www.myfonts.com/fonts/eurotypo/predy/
http://www.myfonts.com/fonts/eurotypo/tansy/
http://www.myfonts.com/fonts/autographis/ysadora/
http://www.myfonts.com/fonts/trial-by-cupcakes/quickpen/
http://www.myfonts.com/fonts/andinistas/bemol/
http://www.myfonts.com/fonts/stephen-rapp/montague-script-bold/
http://www.myfonts.com/fonts/stephen-rapp/hiatus/
http://www.myfonts.com/fonts/fontforecast/santas-pen/
http://www.myfonts.com/fonts/g-type/olicana/
http://www.myfonts.com/fonts/trial-by-cupcakes/anna-clara/
http://www.myfonts.com/fonts/correspondence-ink/belluccia/
http://www.myfonts.com/fonts/debi-sementelli/cantoni/

The source is a card design from the zazzle website. I thought it might be one of their fonts, but it is actually an image provided by the designer. I've contacted the designer to ask, but have had no luck of a response yet.

Here's the link:
http://www.zazzle.com/calligraphy_script_wedding_thank_you_postcard-2392...

And thanks for the alternatives, I'll definitely give those a look.

It looks like http://www.myfonts.com/fonts/emily-lime/carolyna-pro-black/

Well done, Riccardo.

I searched using WhattheFont, but it didn't kick out Carolyna—maybe all the alternate glyphs confused it. Or, once again, MyFonts hasn't added that font to its visual search database yet. I've never found it to be too reliable....

That's the one! Thank you so much for the help.