  High-pressure synthesis techniques have allowed for the growth of samples on
the indium-rich side of (Pb,In)Te, which have increased superconducting
transition temperatures compared to lead-rich compounds. In this study we
present measurements of the temperature dependence of the London penetration
depth $\Delta \lambda(T)$ in the compound In$_{0.8}$Pb$_{0.2}$Te, which shows a
bulk $T_{c,onset}$ of $\sim4.75$ K. The results indicate fully gapped BCS-like
behavior, ruling out odd-parity, topologically nontrivial $A_{2u}$ pairing;
however, odd-parity $A_{1u}$ pairing is still possible. Critical field values
measured below 1 K and other superconducting parameters are also presented.
